diff --git a/ANNOUNCE b/ANNOUNCE
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,43 +1,39 @@
-Subject: Announcing Isabelle2020
+Subject: Announcing Isabelle2021
 To: isabelle-users@cl.cam.ac.uk
 
-Isabelle2020 is now available.
-
-This version introduces many changes over Isabelle2019: see the NEWS
-file for further details. Here are some notable points:
-
-* PIDE: much faster startup of Isabelle/jEdit thanks to more scalable
-session directory structure.
-
-* PIDE: updated Isabelle/VSCode to follow recent moves of VSCode.
-
-* Pure: improved treatment of theorem dependencies and proof terms,
-accessible via command 'thm_deps'.
-
-* Pure: proper treatment of oracles within internal proof objects,
-accessible via command 'thm_oracles'.
+Isabelle2021 is now available.
 
-* HOL: various library improvements.
-
-* HOL: better organization of HOL-Analysis vs. HOL-Complex_Analysis.
-
-* ML: more scalable export artifacts via XML blobs.
-
-* Scala: support for external IDEs based on Gradle (e.g. IntelliJ IDEA).
+This version introduces many changes over Isabelle2020: see the NEWS
+file for further details. Here are various details:
 
-* Scala: support for Ubuntu server applications (Linux-Apache-MySQL-PHP).
-
-* System: Isabelle/Phabricator as self-hosted project management platform.
+* Improved HTML presentation in Isabelle/Scala, using PIDE markup.
 
-* System: update to current Poly/ML 5.8.1 with improved robustness,
-especially on Windows.
+* Improved PDF document preparation in Isabelle/Scala, using LuaLaTeX.
 
-* System: improved support for macOS, notably 10.15 Catalina.
+* Isabelle/jEdit: improved monitoring of Java and ML process.
+
+* Isabelle/jEdit: various IDE feedback improvements.
+
+* Pure: improved handling of named contexts and local syntax bundles.
+
+* HOL: substantially reworked support for Word library.
+
+* HOL: various syntax and library improvements.
+
+* HOL: various Sledgehammer and SMT improvements, with updated external tools.
+
+* HOL: support for Nitpick/Kodkod in Isabelle/Scala.
+
+* ML: routine support for Isabelle/Scala functions in Isabelle/ML.
+
+* System: support for Isabelle/Scala services defined in user-space.
+
+* Experimental support for ARM64 platform on Linux and macOS (Apple Silicon).
 
 
-You may get Isabelle2020 from the following mirror sites:
+You may get Isabelle2021 from the following mirror sites:
 
   Cambridge (UK)       https://www.cl.cam.ac.uk/research/hvg/Isabelle
   Munich (Germany)     https://isabelle.in.tum.de
   Sydney (Australia)   https://mirror.cse.unsw.edu.au/pub/isabelle
   Potsdam, NY (USA)    https://mirror.clarkson.edu/isabelle