Stream: Mirror: Isabelle Development Mailing List

Topic: NEWS: ZGC of Java 21 now used by default

Email Gateway (Mar 20 2025 at 16:37):

From: Makarius <makarius@sketis.net>
* System *

• The Z Garbage Collector (ZGC) of Java 21 is now used by default (see
  also https://wiki.openjdk.org/display/zgc). This should work uniformly
  on all platforms, but requires a reasonably new version of Windows
  (Windows 10 or Windows Server 2019).

This refers to Isabelle/1a4be2516f50.

I've been testing this locally for quite some time, now it is the default.
Technically, it has become possible, because our old Windows Server 2012
(vmnipkow9) has been discontinued.

Makarius

Last updated: Feb 04 2026 at 02:22 UTC