http://www.microsoft.com/downloads/details.aspx?FamilyId=3A1C93FA-7462-47D0-8E56-8DD34C6292F0&displaylang=en http://www.sscli.net/servlets/ProjectListAs for WinForms, the implementation is pretty much entrenched in the current Windows architecture (WndProc) and wouldn't be directly compatible with the way the Mac (Aqua?) does things.