Mikmod is a module player and library supporting many formats, including mod, s3m, it, and xm. Originally a player for MS-DOS, MikMod has been ported to other platforms, such as Unix, Macintosh, BeOS, and Java(!!)
Hammer of Thyrion (uHexen2) is a cross-platform port of Raven Software's Hexen II source. It is based on an older linux port, Anvil of Thyrion. HoT includes countless bug fixes, improved music, sound and video modes, opengl improvements, support for many operating systems and architectures, and documentation among many others.
An effort to unify the development of patches against binutils, gdb, and GCC to support all kind of AmigaOS target platforms (AmigaOS, MorphOS, AROS, etc). Another target is to achieve an integration of these patches to the official development projects.
Free 32/64/16-bit multi-platform Pascal and Object Pascal compiler
A 32/64/16-bit Pascal compiler for Win32/64/CE, Linux, Mac OS X/iOS, Android, FreeBSD, OS/2, Game Boy Advance, Nintendo NDS and DOS; semantically compatible with Delphi, Borland Pascal and Mac Pascal (partially) with extra features, e.g. operator overloading.
AmIDE - Amiga Integrated Development Environment is a modern MUI based IDE system that should make the Amiga developer able to use his favourite Compiler system with a modern looking GUI System with features like filetype handling, Build/Make, TextEd