Posting here, as there is no dedicated GNUStep part in the forum:
https://multixden.blogspot.com/2023/08/gnustep-now-has-badges.htmlCiting from the announcement:
QuoteFinally I got around implementing and committing badge support in GNUStep! I think it is one of the fine additions Apple did to the original OpenStep spec
While Apple had it since MacOS 10.5, GNUstep didn't and GNUMail had to manage 3 different code paths: One for GNUstep, one for 10.4 Mac and one for 10.5 and later which I implemented myself, since GNUMail originally didn't have it. First, I with Fred and Richard brought up GNUmail code to match the 10.4 code path, which is generic and just draws the Icon. To do this, I had to change the code, since ImageReps are not writable in GNUstep, so NSCustomImageRep had to be used and it woks both on GNUstep and on Mac.