Two former commercials products released as open source by it's author.
UIK : User Interface Kit for Amiga OS - An object engine :
https://github.com/JeanMichelForgeas/UIK
Azur : Text editor for Amiga OS :
https://github.com/JeanMichelForgeas/AZur
Thanks goes to Jean-Michel Forgeas who have decided to Open Source it's programs.