NEWS

--- a/NEWS	Sat Oct 30 12:26:56 2021 +0200
+++ b/NEWS	Sat Oct 30 13:12:22 2021 +0200
@@ -499,6 +499,9 @@
 
 *** System ***
 
+* Update to Poly/ML 5.9 with improved support for ARM on Linux. (On
+macOS the Intel version works smoothly with Rosetta 2, as before.)
+
 * Update to OpenJDK 17: the current long-term support version of Java.
 
 * Perl is no longer required by Isabelle proper, and longer provided by