See the link below to my pet project, tomboy-ng.
Tomboy Notes was big ten years a go, it was built on Mono and GTK2, ran on Windows and Linux and briefly MacOS pre OSX10. Ubuntu ran a note syning server for it, and it was shipped, by default with quite a lot of linux distros. Had a team of, perhaps, 10 active devs.
But it got harder and harder to keep up with the changes to mono (tracking C#) and getting a GTK2 running on windows became awkward too. So, slowly it died, still has a few users, no new release for four or five years.
In discussion with someone, I said I would try for a new release but when confronted with the C# code, I was lost. I looked around for a replacement, discovered FPC/Lazarus, remembered doing some Pascal at Uni, felt safe. Caused a few laughs on the Tomboy mailing list, but reasonably quickly had a mockup working, now in its 36th release !
Good decision ? you better believe it !
Davo