diff --git a/admin/site/config.json b/admin/site/config.json
--- a/admin/site/config.json
+++ b/admin/site/config.json
@@ -1,60 +1,59 @@
 {
     "baseURL": "/",
     "languageCode": "en-gb",
     "title": "Archive of Formal Proofs",
     "theme": "afp",
     "publishDir": "..",
     "taxonomies": {
         "author": "authors",
         "topic": "topics",
         "dependency": "dependencies"
     },
     "params": {
         "description": "A collection of proof libraries, examples, and larger scientific developments, mechanically checked in the theorem prover Isabelle.",
         "images": [
             "/images/afp.png"
         ],
         "title": "Archive of Formal Proofs",
         "mainSections": ["entries"],
         "afpUrls": {
           "html": "https://www.isa-afp.org/browser_info/current/AFP",
           "htmlDevel": "https://devel.isa-afp.org/browser_info/current/AFP"
-        },
-        "devel": true
+        }
     },
     "markup": {
         "goldmark": {
             "renderer": {
                 "unsafe": true
             }
         }
     },
     "menu": {
         "main": [
            {
               "name": "Topics",
               "url": "/topics/",
               "weight": 2
            }
         ]
     },
     "outputs": {
         "home": ["html", "rss", "json"],
         "taxonomyTerm": ["html", "json"]
     },
     "related": {
         "includeNewer": true,
         "indices": [
             {
               "name": "topics",
               "weight": 1
             },
             {
               "name": "keywords",
               "weight": 3
             }
         ],
         "threshold": 80,
         "toLower": true
     }
 }
\ No newline at end of file
diff --git a/admin/site/themes/afp/assets/sass/main.scss b/admin/site/themes/afp/assets/sass/main.scss
--- a/admin/site/themes/afp/assets/sass/main.scss
+++ b/admin/site/themes/afp/assets/sass/main.scss
@@ -1,1073 +1,1088 @@
 //colors
 $theme: hsl(242, 27%, 24%);
 $theme-hover: hsl(241, 26%, 36%);
 $theme-lightest: hsl(261, 36%, 86%);
 $theme-focus: #acabcf;
 $link: #0645ad;
 $link-hover: #0000ee;
 $link-visited: #42047c;
 $white: #fff;
 $lightest-grey: #f2f2f2;
 $lighter-grey: #ddd;
 $light-grey: #bbb;
 $dark-grey: #777;
 $darker-grey: #555;
 $darkest-grey: #303030;
 $black: #000;
 $black_15: rgba(0, 0, 0, 0.15);
 
 //fonts
 $sans-serif: "Open Sans", sans-serif;
 $monospace: "Consolas", monospace;
 $OpenSans: "Open Sans";
 
 $light: 300;
 $normal: 400;
 $bold: 700;
 
 $border-bottom: 2px $darker-grey solid;
 
 %code {
   font-family: $monospace;
   background-color: $lightest-grey;
   color: $darkest-grey;
 }
 
 %button {
   border: 1px solid $dark-grey;
   font-size: 1rem;
   vertical-align: middle;
   background-color: $white;
   color: $black;
   line-height: 0;
   font-family: $sans-serif;
 }
 
 %button-image {
   position: relative;
   top: 0.12em;
   left: 5px;
   padding-right: 5px;
 }
 
 %sticky {
     position: sticky;
     top: 0;
     background-color: $white;
     margin: 0;
     padding-bottom: 0.5rem;
 }
 
 @font-face {
   font-family: $OpenSans;
   font-display: swap;
   font-style: normal;
   font-weight: 300;
   src: local(""), url("/font/open-sans-v18-latin-300.woff2") format("woff2"),
   url("/font/open-sans-v18-latin-300.woff") format("woff");
 }
 
 @font-face {
   font-family: $OpenSans;
   font-display: swap;
   font-style: normal;
   font-weight: 400;
   src: local(""), url("/font/open-sans-v18-latin-regular.woff2") format("woff2"),
   url("/font/open-sans-v18-latin-regular.woff") format("woff");
 }
 
 @font-face {
   font-family: $OpenSans;
   font-display: swap;
   font-style: italic;
   font-weight: 400;
   src: local(""), url("/font/open-sans-v18-latin-italic.woff2") format("woff2"),
   url("/font/open-sans-v18-latin-italic.woff") format("woff");
 }
 
 @font-face {
   font-family: $OpenSans;
   font-display: swap;
   font-style: normal;
   font-weight: 700;
   src: local(""), url("/font/open-sans-v18-latin-700.woff2") format("woff2"),
   url("/font/open-sans-v18-latin-700.woff") format("woff");
 }
 
 @font-face {
   font-family: $OpenSans;
   font-display: swap;
   font-style: italic;
   font-weight: 700;
   src: local(""), url("/font/open-sans-v18-latin-700italic.woff2") format("woff2"),
   url("/font/open-sans-v18-latin-700italic.woff") format("woff");
 }
 
 *::selection {
   background-color: $theme;
   color: $white;
 }
 
 body {
   color: $black;
   background: $white;
   font-family: $sans-serif;
   display: grid;
   grid-template-columns: #{"max(20%, 200px)"} 1fr;
   grid-template-areas: "sidebar content";
   justify-items: center;
   margin: 0;
 }
 
 aside {
   grid-area: sidebar;
   background-color: $theme;
   width: 20vw;
   margin: 0;
   height: 100%;
   position: fixed;
   top: 0;
   left: 0;
   min-width: 200px;
   word-break: break-all;
   overflow-y: auto;
   color: $white;
 
   nav {
     display: flex;
     flex-direction: column;
     justify-content: space-between;
     height: 100vh;
   }
 
   ul {
     list-style: none;
     padding: 0;
   }
 
   li {
     padding: 0.5em 2rem;
 
     &:hover {
       background-color: $theme-hover;
     }
   }
 
   .active {
     background-color: $theme-hover;
   }
 
   div > a {
     display: block;
     text-align: center;
   }
 
   a {
     &:link,
     &:visited {
       color: $white;
     }
 
     &:focus {
       outline: 1px $theme-focus solid;
       outline-offset: 3.5px;
     }
   }
 
   hr {
     margin: 2rem;
     border: none;
     border-top: 2px solid $dark-grey;
   }
 }
 
 .logo {
   width: 40%;
   height: auto;
   padding: 10%;
   max-width: 160px;
 }
 
 li {
   margin: 0.25em 0;
 }
 
 header {
   border-bottom: $border-bottom;
   margin-bottom: 20px;
   padding: 0.5rem 0;
 
   > div {
     display: flex;
     justify-content: space-between;
     padding: 0.5rem 0;
   }
 
   form {
     padding: 0.5rem 0;
     float: right;
   }
 
   h1 {
     padding: 0.5rem 0;
     margin: 0;
     clear: both;
     line-height: 2.75rem;
   }
 
   #searchInput {
     height: 2rem;
     padding: 7px;
     width: 175px;
   }
 
   #searchButton {
     height: 2rem;
     padding: 7px;
     width: 2rem;
 
     &:hover {
       background-color: $lighter-grey;
     }
 
     &:active {
       background-color: $light-grey;
     }
   }
 
   div p {
     margin: 0;
   }
 }
 
 .content {
   grid-area: content;
   margin: 0 auto 2rem;
   width: 50vw;
   min-width: 550px;
 
   div {
     line-height: 1.35em;
     width: 100%;
 
     h1 {
       border-bottom: $border-bottom;
     }
   }
 
   > div {
     form {
       margin: 2rem auto 0;
       width: 50%;
       min-width: 290px;
       padding: 1rem 0;
     }
 
     #searchButton {
       height: 2.5rem;
       width: 25%;
       min-width: 70px;
       background: $theme;
       color: $white;
       border: 1px $theme solid;
     }
 
     #searchInput {
       height: 2.5rem;
       width: 75%;
     }
   }
 
   .popup {
     background: $white;
     box-shadow: 0 0 8px 0 $black_15, 0 4px 10px 0 $black_15;
     padding: 2.5rem;
     display: block;
     width: auto;
     min-width: 300px;
     max-width: 90vw;
     max-height: 75vh;
     position: fixed;
     left: 50%;
     top: 50%;
     transform: translate(-50%, -50%);
     overflow-y: auto;
   }
 
   .chart {
     min-width: 400px;
     width: 100%;
     min-height: 400px;
     max-height: 50vh;
     background: $white;
     margin: 20px auto 40px;
     border: 1px solid $black;
     position: relative;
   }
 
   .statsnumber {
     text-align: right;
     padding-right: 1rem;
   }
 
   ul {
     list-style-type: none;
   }
 
   li {
     word-break: break-all;
   }
 
   li::before {
     content: "–";
     position: absolute;
     margin-left: -1.3em;
   }
 }
 
 .entries {
   > div {
     display: grid;
     grid-template-columns: 3fr 1fr;
   }
 
   main {
     padding-right: 2%;
     max-width: 90ch;
 
     div {
       margin: 1rem 0;
     }
   }
 
   nav {
     width: 130px;
     margin-left: auto;
 
     h4 {
       color: $darker-grey;
       font-weight: $normal;
     }
   }
 }
 
 .theories {
   grid-template-columns: 20% 80%;
   justify-content: normal;
 
   .collapsible.collapsed {
     display: none;
   }
 
   .invertible.collapsed {
     transform: scale(1,-1);
   }
 
   .collapse-container.collapsed {
     .collapsible {
       display: none;
     }
     .invertible {
       transform: scale(1,-1);
     }
   }
 
   .content {
     min-width: clamp(80ch,50vw, 50vw);
     width: auto;
     max-width: 75vw;
     margin: 0 0 2rem 4vw;
   }
 
   h2 {
     @extend %sticky;
     padding-top: 0.5rem;
     border-bottom: 1px $light-grey solid;
 
     svg {
       height: 2rem;
       width: 20px;
       position: absolute;
       right: 1em;
       stroke: $dark-grey;
       transition: transform 100ms;
     }
   }
 
   main {
       > div {
           margin-bottom: 1rem;
       }
   }
 
   aside {
     word-break: normal;
     z-index: 1;
     overflow-x: hidden;
 
     .logo {
         padding-top: 2rem;
         padding-bottom: 2rem;
         width: 100px;
 
         @media (min-width: 1800px) {
             width: 150px;
         }
     }
 
     > div {
       margin-right: 1rem;
     }
 
     &:hover {
       min-width: fit-content;
       div {
         min-width: fit-content;
       }
     } 
 
     ul {
       margin-left: 1.75rem;
     }
 
     li {
       padding: 0;
 
       &:hover {
         background-color: $theme;
       }
 
       > a:hover {
         background-color: $theme-hover;
       }
 
       a {
         padding: 0.5em 0;
         display: inline-block;
         width: 100%;
       }
     }
   }
 
   @media (max-width: 875px) {
     padding: 0;
     grid-template-columns: 1fr;
 
     .content {
       min-width: 350px;
       max-width: 100vw;
       margin: 80px 0;
     }
 
     nav {
       display: none;
     }
   }
 }
 
 .links {
   button {
     display: inline-block;
     margin: 0.5rem 0;
   }
 
   a {
     display: inline-block;
     margin: 0.5rem 0;
   }
 }
 
 .popUpButton {
   &:visited {
     color: $white;
   }
 
   &:link {
     border: none;
     padding: 0.75rem 0;
     background-color: $theme;
     color: $white;
     cursor: pointer;
     text-align: center;
     transition: background-color 200ms ease, transform 150ms ease;
     font-weight: $bold;
     font-size: 0.9rem;
     width: 130px;
   }
 
   &:active {
     transform: scale(0.98);
   }
 }
 
 a {
   &:link {
     color: $link;
     text-decoration: none;
     font-weight: $bold;
   }
 
   &:visited {
     color: $link-visited;
   }
 
   &:hover {
     color: $link-hover;
   }
 }
 
 h1 {
   margin: 1.5em 0 0 0;
   font-size: 2em;
   padding-bottom: 20px;
 
   span.first {
     font-size: 2.3rem;
   }
 }
 
 h2 {
   margin: 1.5em 0 0 0;
   padding: 0;
   line-height: normal;
 }
 
 h3 {
   margin: 1.5em 0 0 0;
   font-stretch: normal;
   font-size: larger;
   padding: 0;
   font-weight: $light;
 
   &:first-child {
     margin: 0.5rem 0 0 0;
   }
 }
 
 h4 {
   margin: 1.5em 0 0 0;
   margin-bottom: 0.5ex;
   font-weight: $bold;
 }
 
 .popup {
   h2 {
     margin-top: 0;
   }
 
   .close {
     position: absolute;
     width: 20px;
     height: 20px;
     top: 2rem;
     right: 2rem;
     transition: all 200ms;
     font-size: 24px;
     font-weight: $bold;
     color: $darker-grey;
     text-align: center;
 
     &:hover {
       color: $darkest-grey;
     }
   }
 }
 
 #downloadPopUp {
   a[download] {
     display: block;
     width: 154px;
     margin: 2.5rem auto 0;
   }
 }
 
 .year {
   @extend %sticky;
   padding-top: 2rem;
   border-bottom: $border-bottom;
 }
 
 img {
   max-width: 90%;
 }
 
 pre {
   @extend %code;
   padding: 1rem;
   overflow: auto;
 
   &.bibtex {
     white-space: pre;
     border-width: thin;
     border-style: solid;
   }
 
   &.code {
     white-space: pre;
     padding: 10px 2px;
   }
 }
 
 code {
   padding: 1px 2px 2px;
   @extend %code;
 }
 
 blockquote {
   border: 2px solid $lighter-grey;
   padding: 1rem 2rem;
   margin: auto 0;
 }
 
 tr:nth-child(even) {
   background-color: $lightest-grey;
 }
 
 .nobr {
   white-space: nowrap;
 }
 
 .largeTopMargin {
   margin-top: 48px;
 }
 
 .searchPage {
   > div {
     display: grid;
     grid-template-columns: 3fr #{"max(25%, 175px)"};
     grid-template-rows: 150px 1fr;
     grid-template-areas:
       "search search"
       "entries sidebar";
   }
 
   form {
     grid-area: search;
   }
 
   #search-main {
     grid-area: entries;
     padding-right: 2rem;
     box-sizing: border-box;
   }
 
   #search-results {
     > div {
       position: relative;
       margin: 1.5rem 0;
       border-bottom: 2px $lighter-grey solid;
       padding-bottom: 1.5rem;
     }
 
     div + div {
       margin-top: 1rem;
     }
 
     .title,
     .subtitle {
       display: flex;
       justify-content: space-between;
       align-items: center;
     }
 
     .subtitle {
       color: $dark-grey;
       font-size: 0.875em;
 
       > p {
         margin: 0;
       }
     }
 
     a[download] {
       padding: 5px 7.5px;
       flex-shrink: 0;
       margin-left: 1em;
     }
   }
 
   #search-sidebar {
     grid-area: sidebar;
   }
 }
 
 a[download] {
   display: inline-block;
   color: $black;
   height: 22px;
   padding: 4px 7px;
   @extend %button;
 
   &:focus {
     outline: none;
     box-shadow: 0 0 0 2px #c5c4ddbb;
   }
 
   &:hover,
   &:active {
     background-color: $light-grey;
     color: $black;
   }
   &:after {
     content: url("/images/download.svg");
     @extend %button-image;
   }
 }
 
 .entry {
   display: flex;
   align-items: center;
   margin-top: 1.35rem;
 
   a[download] {
     position: absolute;
     top: 0;
     right: 0;
   }
 
   .date {
     text-align: right;
     width: 15%;
     min-width: 6ch;
     font-family: $monospace;
   }
 
   h5 {
     font-size: initial;
     display: initial;
   }
 }
 
 .form-container {
   width: 290px;
   text-align: left;
 }
 
 #searchInput {
   @extend %button;
   border-right: none;
   font-family: $sans-serif;
   padding: 0.5em;
 }
 
 #searchButton {
   @extend %button;
   cursor: pointer;
 
   &:focus {
     outline: none;
     box-shadow: 0 0 0 2px #c5c4ddbb;
   }
 
   img {
     max-width: 1rem;
   }
 }
 
 button {
   @extend %button;
   height: 2rem;
   padding: 7px;
   font-weight: $bold;
   cursor: pointer;
 
   &:hover {
     background-color: $lighter-grey;
   }
 
   &:active {
     background-color: $light-grey;
   }
 
   &:focus {
     outline: none;
     box-shadow: 0 0 0 2px #c5c4ddbb;
   }
 }
 
 button[copy] {
   &:after {
     content: url("/images/copy.svg");
     @extend %button-image;
   }
 }
 
 #searchInputautocomplete-list {
   width: 214px;
   position: absolute;
   margin-bottom: 24px;
   padding: 8px 0;
   background-color: $white;
   border: 1px solid $lighter-grey;
   box-shadow: 0 2px 4px $black_15;
   z-index: 1;
 
   div {
     width: auto;
     padding: 8px 12px;
     line-height: 16px;
     cursor: pointer;
 
     &:hover {
       background: $lighter-grey;
     }
   }
 }
 
 .autocomplete-active {
   background: $lighter-grey;
 }
 
 .item-text {
   width: 85%;
 }
 
 .date {
   color: $darker-grey;
   font-size: 14px;
 }
 
 .overlay {
   position: fixed;
   top: 0;
   bottom: 0;
   left: 0;
   right: 0;
   background: $black_15;
   transition: opacity 200ms;
   visibility: hidden;
   opacity: 0;
 
   .cancel {
     position: absolute;
     width: 100%;
     height: 100%;
     cursor: pointer;
   }
 
   &:target {
     visibility: visible;
     opacity: 1;
   }
 }
 
+.status-ok {
+  background-color: #00FF99;
+  padding: 8px;
+}
+
+.status-skipped {
+  background-color: #FFFF99;
+  padding: 8px;
+}
+
+.status-failed {
+  background-color: #DD2222;
+  padding: 8px;
+}
+
 iframe {
   width: 100%;
   height: 90vh;
 }
 
 .loader {
   margin: 24px 24px 0 0;
   height: 6px;
   position: relative;
   display: block;
   background-color: $theme;
   border-radius: 4px;
   overflow: hidden;
 
   .animation {
     background-color: $light-grey;
 
     &:before {
       content: '';
       position: absolute;
       background-color: inherit;
       top: 0;
       left: 0;
       bottom: 0;
       will-change: left, right;
       animation: loader 2s linear infinite;
     }
   }
 }
 
 @keyframes loader {
   0% {
     left: -20%;
     right: 100%;
   }
   100% {
     left: 100%;
     right: -20%;
   }
 }
 
 #menuToggle {
   input,
   label {
     display: none;
   }
 
   > .logoLink, img[alt="Search"] {
     display: none;
   }
 
   > #menu {
     box-shadow: 0 .5rem 1rem rgba(0,0,0,.15);
   }
 
   form {
     display: none;
   }
 }
 
 @media (max-width: 650px) {
   .content {
     width: 90%;
     min-width: 350px;
   }
 
   .searchPage {
     > div {
       display: grid;
       grid-template-columns: 1fr;
       grid-template-rows: 150px auto auto ;
       grid-template-areas:
         'search'
         'sidebar'
         'entries';
     }
   }
 }
 
 @media (max-width: 875px) {
   body {
     grid-template-columns: 1fr;
     grid-template-areas: 'content';
   }
 
   aside {
     height: 4rem;
     width: 100vw;
     overflow-y: visible;
     z-index: 1;
   }
 
   header {
     form {
       display: none;
     }
   }
 
   .content {
     margin-top: 80px;
   }
 
   .entries {
     > div {
       display: grid;
       grid-template-rows: auto auto;
       grid-template-columns: 1fr;
     }
 
     nav {
       margin-left: 0;
     }
   }
 
     
   .largeTopMargin {
     margin-top: 0;
   }
 
   #banner {
     left: 0;
     width: 100vw;
     height: 75px;
 
     p {
       line-height: normal;
       margin: 1rem;
     }
   }
 
   #menuToggle {
     background: $theme;
     display: block;
     position: relative;
     top: 0;
     left: 0;
     z-index: 1;
     height: 80px;
     user-select: none;
     width: 100vw;
     a {
       text-decoration: none;
       transition: color 0.3s ease;
     }
     .logoLink {
       height: 3rem;
       max-width: 50vw;
       top: 1rem;
       left: 0;
       right: 0;
       margin-left: auto; 
       margin-right: auto;
 
 
       img {
         padding: 0;
         height: 3rem;
         object-fit: contain;
       }
     }
 
     .logoLink, input, label, a[href="/search"] {
       display: block;
       position: absolute;
       z-index: 2;
     }
 
     input, label, a[href="/search"] {
       width: 24px;
       height: 24px;
       top: 28px;
     }
 
     input,label { 
       left: 28px;
       cursor: pointer;
     }
 
     a[href="/search"] {
       right: 28px;
       filter: invert(1);
     }
 
     a[href="/search"] img, label img {
       width: 100%;
     }
 
     input {
       opacity: 0;
       &:checked {
         ~ nav {
           left: 0;
         }
       }
     }
     
     label span {
         display: none;
     }
   }
   #menu {
     height: 100vh;
     position: absolute;
     top: 0;
     left: 0;
     padding-top: 80px;
     box-sizing: border-box;
     min-width: 200px;
     width: 50vw;
     max-width: 350px;
     min-height: 355px;
     background: $theme;
     left: -100%;
     transition: left 0.3s ease;
 
     .logoLink {
       display: none;
     }
   }
 }
diff --git a/admin/site/themes/afp/layouts/entries/single.html b/admin/site/themes/afp/layouts/entries/single.html
--- a/admin/site/themes/afp/layouts/entries/single.html
+++ b/admin/site/themes/afp/layouts/entries/single.html
@@ -1,134 +1,154 @@
 {{- define "main" -}}
 {{- $site := . -}}
 {{- $path := .Site.Params.afpUrls.html -}}
-{{- if eq .Site.Params.devel true -}}
+{{- if isset .Site.Data "status" -}}
   {{- $path = .Site.Params.afpUrls.htmlDevel -}}
 {{- end -}}
 {{- $entry_name := .File.BaseFileName -}}
 <main>
+  {{- if isset .Site.Data "status" -}}
+  <strong>
+    This is a development version of this entry. It might change over time and is not stable. Please refer to release versions for citations.
+  </strong>
+  {{- end -}}
   <h3>Abstract</h3>
 
   <div class="abstract mathjax_process">{{- trim .Params.abstract "\n" | safeHTML -}}</div>
   {{- if (eq .Params.licence "BSD") -}}
   <a href="http://isa-afp.org/LICENSE">BSD License</a>
   {{- else if (eq .Params.license "LGPL") -}}
   <a href="http://isa-afp.org/LICENSE.LGPL">GNU Lesser General Public License (LGPL)</a>
   {{- else -}}
     {{- printf "%s License" .Params.license -}}
   {{- end -}}
 
   {{- with .Params.extra -}}
   {{- range $key, $value := . -}}
   <h3>{{- humanize $key -}}</h3>
 
   <p>{{- $value | safeHTML -}}</p>
   {{- end -}}
   {{- end -}}
 
   {{- $Scratch := newScratch -}}
   
   {{- with .Params.dependencies -}}
     <h3>Depends On</h3><ul>
       {{- range . -}}
       <li>{{- printf "[%s](/entries/%s.html)" . . | $.Page.RenderString -}}</li>
       {{- end -}}
     </ul>
   {{- end -}}
 
   {{- with (index .Site.Taxonomies.dependencies (urlize $entry_name)) -}}
     <h3>Used by</h3>
     <ul>
       {{- range . -}}
       <li>{{- printf "[%s](%s)" .File.BaseFileName .RelPermalink | $.Page.RenderString -}}</li>
       {{- end -}}
     </ul>
   {{- end -}}
 
   {{- with .Params.topics -}}
   <h3>Topics</h3>
   <ul>
     {{- range . -}}
     <li>{{- printf "[%s](/topics/%s)" . (urlize .) | $.Page.RenderString -}}</li>
     {{- end -}}
   </ul>
   {{- end -}}
 
   <h3>Theories</h3>
   <ul>
     {{ $file := printf "assets/theories/%s.html" $entry_name}}
     {{- with .Params.theories -}}
     {{- range . -}}
     <li>{{- printf "[%s](%s/theories#%s)" . (urlize $entry_name) . | $.Page.RenderString -}}</li>
     {{- end -}}
     {{- end -}}
   </ul>
 
   {{ $related := .Site.RegularPages.Related . | first 3 }}
   {{ with $related }}
   <h3>Related Entries</h3>
   <ul>
     {{ range . }}
     <li>{{- printf "[%s](%s)" .Title .RelPermalink | $.Page.RenderString -}}</li>
     {{ end }}
   </ul>
   {{ end }}
 </main>
 
-
+{{- if isset .Site.Data "status" -}}
+  <nav>
+  {{- $status := "none" -}}
+  {{- range where .Site.Data.status.entries "entry" $entry_name -}}
+    {{- $status = .status -}}
+  {{- end -}}
+    <div class="status-{{ $status }}">
+      <p>Status: <strong>{{- $status -}}</strong></p>
+      <p>{{ .Site.Data.status.build_data.time }}</p>
+      <p>Isabelle/<wbr>{{ .Site.Data.status.build_data.isabelle_id }}</p>
+      <p>AFP/<wbr>{{ .Site.Data.status.build_data.afp_id }}</p>
+      <p><a href="{{ .Site.Data.status.build_data.url }}">{{ .Site.Data.status.build_data.job }}</a></p>
+    </div>
+  </nav>
+{{- else -}}
 <nav class='links'>
   <a class='popUpButton' href="#citePopUp">Cite</a>
   <a class='popUpButton' href="#downloadPopUp">Download</a>
   <h4>PDFs</h4>
   <a href="{{- $path -}}/{{- $entry_name -}}/outline.pdf">Proof
     outline</a>
   <a href="{{- $path -}}/{{- $entry_name -}}/document.pdf">Proof
     document</a>
   <a href="{{- $path -}}/{{- $entry_name -}}/session_graph.pdf">Dependencies</a>
 </nav>
 
 <div id="citePopUp" class="overlay">
   <a class="cancel" href="#"></a>
   <div class="popup">
     <h2>Cite</h2>
     <a class="close" href="#">&times;</a>
     <div>
       <p style="display:none;" id="bibtexFileName">{{- $entry_name -}}-AFP</p>
       <pre id="copyText">@article{{- "{" -}}{{- $entry_name -}}-AFP,
   author  = {{ "{" -}}{{- delimit .Params.authors ", " | replaceRE "(, )([^,]+$)" " and $2" -}}},
   title   = {{ "{" -}}{{- htmlUnescape .Params.title -}}},
   journal = {Archive of Formal Proofs},
   month   = {{ dateFormat "January" .Params.date -}},
   year    = {{ dateFormat "2006" .Params.date -}},
   note    = {\url{http://isa-afp.org/entries/{{- $entry_name -}}.html},
             Formal proof development},
   ISSN    = {2150-914x},
 }</pre>
       <button id="copyBibtex">Copy</button> <a id="downloadBibtex">Download</a>
     </div>
   </div>
 </div>
 
 <div id="downloadPopUp" class="overlay">
   <a class="cancel" href="#"></a>
   <div class="popup">
     <h2>Download</h2>
     <a class="close" href="#">&times;</a>
     <a href="https://isa-afp.org/release/afp-{{- $entry_name -}}-current.tar.gz" download>Download latest</a>
     {{ with .Params.olderReleases -}}
     <p>Older releases:</p>
     <ul>
       {{- range $map := . -}}
       {{- range $key, $value := $map -}}
       <li>Isabelle {{- $key -}}:
         <a href="https://isa-afp.org/release/afp-{{- $entry_name -}}-{{- $value -}}.tar.gz">
           afp-{{- $entry_name -}}-{{- $value -}}.tar.gz
         </a>
       </li>
       {{- end -}}
       {{- end -}}
     </ul>
     {{- end }}
   </div>
 </div>
+{{- end -}}
 
 {{- end -}}
diff --git a/admin/site/themes/afp/layouts/index.html b/admin/site/themes/afp/layouts/index.html
--- a/admin/site/themes/afp/layouts/index.html
+++ b/admin/site/themes/afp/layouts/index.html
@@ -1,38 +1,48 @@
 {{- define "main" -}}
 <p>
   The Archive of Formal Proofs is a collection of proof libraries, examples, and larger scientific
   developments,
   mechanically checked in the theorem prover <a href="http://isabelle.in.tum.de/">Isabelle</a>. It
   is organized in the way
   of a scientific journal, is indexed by <a href="http://dblp.uni-trier.de/db/journals/afp/">dblp</a> and has an
   ISSN:
   2150-914x. Submissions are refereed and we encourage companion AFP submissions to conference and journal
   publications. To cite an entry, please use the <a href="/help/#citing-entries">preferred citation style</a>.
 </p>
 
+{{- if isset .Site.Data "status" -}}
+<p>
+<strong>
+This is the development version of the archive, referring to a recent Isabelle development version.
+Some entries may not be in a working state.
+The main archive is available from the <a href="http://www.isa-afp.org/">front page</a>.
+</strong>
+</p>
+{{- end -}}
+
 <form autocomplete="off" action="{{ "search" | absURL }}">
   <div class='form-container'>
     <input id="searchInput" type="search" size="31" maxlength="255" value="" aria-label="Search the AFP" list="autocomplete"><button
       id="searchButton" type="button">Search</button>
     <datalist id="autocomplete">
     </datalist>
   </div>
 </form>
 
 {{- range (where site.RegularPages "Type" "in" site.Params.mainSections).GroupByDate "2006" -}}
 <div>
   <h2 class="year">{{- .Key -}}</h2>
   {{- range .Pages }}
   <article class="entry">
     <div class="item-text">
       <h5><a class="title" href="{{ .RelPermalink }}">{{- htmlUnescape .Title -}}</a></h5> <br>
         by {{ partial "authors.html" (dict "site" . "authors" .Params.authors) -}}
     </div>
     <span class="date">
       {{ .Date.Format "Jan 02" }}
     </span>
   </article>
   {{- end -}}
 </div>
 {{- end -}}
 {{- end -}}
\ No newline at end of file
diff --git a/admin/site/themes/afp/layouts/partials/theory-navigation.html b/admin/site/themes/afp/layouts/partials/theory-navigation.html
--- a/admin/site/themes/afp/layouts/partials/theory-navigation.html
+++ b/admin/site/themes/afp/layouts/partials/theory-navigation.html
@@ -1,32 +1,32 @@
 {{- $entry_name := .File.BaseFileName -}}
 {{- $site := . -}}
 {{- $path := .Site.Params.afpUrls.html -}}
-{{- if eq .Site.Params.devel true -}}
+{{- if isset .Site.Data "status" -}}
   {{- $path = .Site.Params.afpUrls.htmlDevel -}}
 {{- end -}}
 <div id="menuToggle">
   <a href="{{- .Site.BaseURL -}}" class='logoLink'>
     <img src="{{- .Site.BaseURL -}}images/afp.png" alt='Logo of the Archive of Formal Proofs' class="logo">
   </a>
   <nav>
   <div>
     <a href="{{- .Site.BaseURL -}}">
       <img src="{{- .Site.BaseURL -}}images/afp.png" alt='Logo of the Archive of Formal Proofs'
         class="logo">
     </a>
     {{ $currentPage := . -}}
     <ul>
       <li><a href="{{- .Site.BaseURL -}}entries/{{- $entry_name | urlize -}}">Return to entry</a></li>
     </ul>
     <hr>
     <ul id="theory-navbar" class="list-group"></ul>
   </div>
   <ul>
     <li><a href="{{- $path -}}/{{- $entry_name -}}/outline.pdf">Proof
       outline</a></li>
     <li><a href="{{- $path -}}/{{- $entry_name -}}/document.pdf">Proof
       document</a></li>
     <li><a href="{{- $path -}}/{{- $entry_name -}}/session_graph.pdf">Session dependencies</a></li>
   </ul>
   </nav>
 </div>
diff --git a/admin/site/themes/afp/layouts/theories/single.html b/admin/site/themes/afp/layouts/theories/single.html
--- a/admin/site/themes/afp/layouts/theories/single.html
+++ b/admin/site/themes/afp/layouts/theories/single.html
@@ -1,13 +1,13 @@
 {{- define "main" -}}
 {{- $site := . -}}
 {{- $path := .Site.Params.afpUrls.html -}}
-{{- if eq .Site.Params.devel true -}}
+{{- if isset .Site.Data "status" -}}
   {{- $path = .Site.Params.afpUrls.htmlDevel -}}
 {{- end -}}
 <main id="theories">
   {{- range .Params.theories }}
   <a id="{{ . }}" href="{{ $path }}/{{ $site.File.BaseFileName }}/{{ . }}.html"><h2>{{ . }}</h2></a>
   {{- end -}}
 </main>
 
 {{- end -}}
\ No newline at end of file
diff --git a/tools/afp_site_gen.scala b/tools/afp_site_gen.scala
--- a/tools/afp_site_gen.scala
+++ b/tools/afp_site_gen.scala
@@ -1,265 +1,281 @@
 package afp
 
 
 import isabelle._
 
 
 object AFP_Site_Gen
 {
   /* json */
 
   object JSON
   {
     type T = isabelle.JSON.T
 
     object Object
     {
       type T = isabelle.JSON.Object.T
     }
 
     def from_authors(authors: List[Metadata.Author]): T =
       Metadata.TOML.from_authors(authors)
 
     def from_topics(topics: List[Metadata.Topic]): T =
       Metadata.TOML.from_topics(topics)
 
     def from_affiliations(affiliations: List[Metadata.Affiliation]): Object.T =
     {
       Utils.group_sorted(affiliations, (a: Metadata.Affiliation) => a.author).view.mapValues(author_affiliations =>
       {
         val homepage = author_affiliations.collectFirst { case Metadata.Homepage(_, _, url) => url }
         val email = author_affiliations.collectFirst { case Metadata.Email(_, _, address) => address }
 
         isabelle.JSON.Object(
           homepage.map(s => List("homepage" -> s)).getOrElse(Nil) :::
             email.map(s => List("email" -> s)).getOrElse(Nil): _*)
       }).toMap
     }
 
     def from_change_history(history: Metadata.Change_History): Object.T =
     {
       if (history.isEmpty) {
         Map.empty
       } else {
         Map("Change history" -> history.map {
           case (date, str) => "[" + date.toString + "] " + str
         }.mkString("\n"))
       }
     }
 
     def from_entry(entry: Metadata.Entry): JSON.Object.T =
       isabelle.JSON.Object(
         "title" -> entry.title ::
           "authors" -> entry.authors.map(_.author).distinct ::
           "affiliations" -> from_affiliations(entry.authors ++ entry.contributors) ::
           (if (entry.contributors.nonEmpty) "contributors" -> entry.contributors.map(_.author).distinct :: Nil
           else Nil) :::
           "date" -> entry.date.toString ::
           "topics" -> entry.topics.map(_.id) ::
           "abstract" -> entry.`abstract` ::
           "license" -> entry.license ::
           (if (entry.releases.nonEmpty)
             "releases" -> entry.releases.map(r => r.isabelle -> r.date.toString).toMap :: Nil
           else Nil) :::
           (if (entry.note.nonEmpty) "note" -> entry.note :: Nil else Nil) :::
           (if (entry.change_history.nonEmpty || entry.extra.nonEmpty)
             "extra" -> (from_change_history(entry.change_history) ++ entry.extra) :: Nil
           else Nil): _*)
 
     def from_keywords(keywords: List[String]): T =
       keywords.zipWithIndex.map
         { case (keyword, i) => isabelle.JSON.Object("id" -> i, "keyword" -> keyword) }
   }
 
 
   /* keyword extraction */
 
   private val replacements = List(
     "<[^>]*>".r -> "",
     "[^\\w\\s()'.,;:-]".r -> " ",
     "\\s+".r -> " ")
 
   def extract_keywords(text: String): List[String] =
   {
     val stripped_text =
       replacements.foldLeft(text) { case (res, (regex, replacement)) => regex.replaceAllIn(res, replacement) }
 
     val arg = quote(stripped_text.replaceAll("\"", "\\\""))
 
     val keyword_cmd = "from keywords import *; print_keywords(" + arg + ")"
 
     Python.run(keyword_cmd).check.out_lines
   }
 
 
   /* site generation */
 
   def afp_site_gen(
     out_dir: Option[Path],
     layout: Hugo.Layout,
+    status_file: Option[Path],
     afp_structure: AFP_Structure,
     progress: Progress = new Progress()): Unit =
   {
     /* add authors */
 
     progress.echo("Preparing authors...")
 
     val authors = afp_structure.load_authors
     val authors_by_id = Utils.grouped_sorted(authors, (a: Metadata.Author) => a.id)
 
     layout.write_data(Path.basic("authors.json"), JSON.from_authors(authors))
 
 
     /* add topics */
 
     progress.echo("Preparing topics...")
 
     val topics = afp_structure.load_topics
     def sub_topics(topic: Metadata.Topic): List[Metadata.Topic] = topic :: topic.sub_topics.flatMap(sub_topics)
 
     val topics_by_id = Utils.grouped_sorted(topics.flatMap(sub_topics), (t: Metadata.Topic) => t.id)
 
     layout.write_data(Path.basic("topics.json"), JSON.from_topics(topics))
 
 
     /* add releases */
 
     progress.echo("Preparing releases...")
 
     val releases_by_entry = afp_structure.load_releases.groupBy(_.entry)
 
 
     /* extract keywords */
 
     progress.echo("Extracting keywords...")
 
     var seen_keywords = Set.empty[String]
     val entry_keywords = afp_structure.entries.map(name =>
     {
       val entry = afp_structure.load_entry(name, authors_by_id, topics_by_id, releases_by_entry)
 
       val Keyword = """\('([^']*)', ([^)]*)\)""".r
       val scored_keywords = extract_keywords(entry.`abstract`).map {
         case Keyword(keyword, score) => keyword -> score.toDouble
         case s => error("Could not parse: " + s)
       }
       seen_keywords ++= scored_keywords.map(_._1)
 
       name -> scored_keywords.filter(_._2 > 1.0).map(_._1)
     }).toMap
     
     seen_keywords = seen_keywords.filter(k => !k.endsWith("s") || !seen_keywords.contains(k.stripSuffix("s")))
     layout.write_static(Path.make(List("data", "keywords.json")), JSON.from_keywords(seen_keywords.toList))
 
     def get_keywords(name: Metadata.Entry.Name): List[String] =
       entry_keywords(name).filter(seen_keywords.contains).take(8)
 
 
     /* add entries and theory listings */
 
     progress.echo("Preparing entries...")
 
     val sessions_structure = afp_structure.sessions_structure
     val sessions_deps = Sessions.deps(sessions_structure)
 
     for (name <- afp_structure.entries) {
       val entry = afp_structure.load_entry(name, authors_by_id, topics_by_id, releases_by_entry)
 
       val deps =
         for {
           session <- afp_structure.entry_sessions(name)
           dep <- sessions_structure.imports_graph.imm_preds(session.name)
           if session.name != dep && sessions_structure(dep).groups.contains("AFP")
         } yield dep
 
       val topo_theories =
         for {
           session <- afp_structure.entry_sessions(name)
           base = sessions_deps(session.name)
           node <- base.session_theories
         } yield node.theory_base_name
 
       val entry_json = JSON.from_entry(entry) ++ isabelle.JSON.Object(
           "dependencies" -> deps.distinct,
           "theories" -> topo_theories,
           "url" -> ("/entries/" + name + ".html"),
           "keywords" -> get_keywords(name))
 
       val theories_json = isabelle.JSON.Object(
         "title" -> entry.title,
         "url" -> ("/entries/" + name.toLowerCase + "/theories"),
         "theories" -> topo_theories)
 
       layout.write_content(Path.make(List("entries", name + ".md")), entry_json)
       layout.write_content(Path.make(List("theories", name + ".md")), theories_json)
     }
 
 
     /* add statistics */
 
     progress.echo("Preparing statistics...")
 
     val statistics_cmd = "from statistics import *; add_statistics(" +
       commas_quote(
         List(
           Path.explode("$AFP_BASE").absolute.implode,
           Path.explode("$AFP").absolute.implode,
           layout.data_dir.implode)) +
       ")"
     Python.run(statistics_cmd).check
     (layout.data_dir + Path.basic("statistics.html")).file.delete()
 
 
     /* project */
 
     progress.echo("Preparing project files")
 
     layout.copy_project()
 
 
+    /* status */
+
+    status_file match {
+      case Some(status_file) =>
+        progress.echo("Preparing devel version...")
+        val status_json = isabelle.JSON.parse(File.read(status_file))
+        layout.write_data(Path.basic("status.json"), status_json)
+    }
+
+
     /* hugo */
 
     out_dir match {
       case Some(out_dir) =>
         progress.echo("Building site...")
 
         Hugo.build(layout, out_dir).check
 
         progress.echo("Finished building site")
       case None =>
         progress.echo("Finished sitegen preparation.")
     }
   }
 
   val isabelle_tool = Isabelle_Tool("afp_site_gen", "generates afp website source", Scala_Project.here, args =>
   {
     var base_dir = Path.explode("$AFP_BASE")
     var hugo_dir = base_dir + Path.make(List("web", "hugo"))
+    var status_file: Option[Path] = None
     var out_dir: Option[Path] = None
 
     val getopts = Getopts("""
 Usage: isabelle afp_site_gen [OPTIONS]
 
   Options are:
     -B DIR       afp base dir (default """" + base_dir.implode + """")
     -H DIR       generated hugo project dir (default """" + hugo_dir.implode + """")
-    -O DIR       output dir (default none)
+    -D FILE      build status file for devel version
+    -O DIR       output dir for optional build (default none)
 
   Generates the AFP website source. HTML files of entries are dynamically loaded.
+  Providing a status file will build the development version of the archive.
   Site will be built from generated source if output dir is specified.
 """,
       "B:" -> (arg => base_dir = Path.explode(arg)),
       "H:" -> (arg => hugo_dir = Path.explode(arg)),
+      "D:" -> (arg => status_file = Some(Path.explode(arg))),
       "O:" -> (arg => out_dir = Some(Path.explode(arg))))
 
     getopts(args)
 
     val afp_structure = AFP_Structure(base_dir)
     val layout = Hugo.Layout(hugo_dir)
     val progress = new Console_Progress()
 
     progress.echo("Preparing site generation in " + hugo_dir.implode)
 
-    afp_site_gen(out_dir = out_dir, layout = layout, afp_structure = afp_structure, progress = progress)
+    afp_site_gen(out_dir = out_dir, layout = layout, status_file = status_file,
+      afp_structure = afp_structure, progress = progress)
   })
 }
\ No newline at end of file
diff --git a/tools/hugo.scala b/tools/hugo.scala
--- a/tools/hugo.scala
+++ b/tools/hugo.scala
@@ -1,79 +1,79 @@
 package afp
 
 
 import isabelle._
 
 
 object Hugo
 {
   val hugo_home = Isabelle_System.getenv("ISABELLE_HUGO")
   val hugo_static = Path.explode("$AFP_BASE") + Path.make(List("admin", "site"))
 
   class Layout private(private[Hugo] val src_dir: Path)
   {
     private def write(file: Path, content: String): Unit =
     {
       val path = src_dir + file
       if (!path.dir.file.exists()) path.dir.file.mkdirs()
       File.write(path, content)
     }
 
     val data_dir = src_dir + Path.basic("data")
 
     def write_data(file: Path, content: JSON.T): Unit =
       write(Path.basic("data") + file, isabelle.JSON.Format(content))
 
     val content_dir = src_dir + Path.basic("content")
 
     def write_content(file: Path, content: JSON.T): Unit =
       write(Path.basic("content") + file, isabelle.JSON.Format(content))
 
     val static_dir = src_dir + Path.basic("static")
     
     def write_static(file: Path, content: JSON.T): Unit =
       write(Path.basic("static") + file, isabelle.JSON.Format(content))
 
     def copy_project(): Unit =
     {
       if (hugo_static.canonical != src_dir) {
         for {
           file <- List(
             List("content", "_index.md"),
             List("content", "about.md"),
-            List("content", "contribution.md"),
+            List("content", "submission.md"),
             List("content", "download.md"),
             List("content", "help.md"),
             List("content", "search.md"),
             List("content", "statistics.md"),
             List("content", "submission.md"),
             List("themes"),
             List("config.json"))
         } Isabelle_System.copy_dir(hugo_static + Path.make(file), src_dir + Path.make(file))
       }
     }
   }
 
   object Layout
   {
     def apply(src_dir: Path = Path.explode("$AFP_BASE") + Path.make(List("web", "hugo"))): Layout =
       new Layout(src_dir.canonical)
   }
 
   private lazy val exec =
     Path.explode(proper_string(hugo_home).getOrElse(error("No hugo component found"))) + Path.basic("hugo")
 
   def build(layout: Layout, out_dir: Path = Path.explode("$AFP_BASE") + Path.basic("web")): Process_Result =
   {
     Isabelle_System.bash(
       exec.implode + " -s " + quote(layout.src_dir.implode) + " -d " + quote(out_dir.canonical.implode))
   }
 
   def watch(layout: Layout, out_dir: Path = Path.explode("$AFP_BASE") + Path.basic("web"),
     progress: Progress = new Progress()): Process_Result =
   {
     Isabelle_System.bash(
       exec.implode + " server -s " + quote(layout.src_dir.implode) + " -d " + quote(out_dir.canonical.implode),
       progress_stdout = progress.echo,
       progress_stderr = progress.echo_warning)
   }
 }
\ No newline at end of file