MilkyTracker - MilkyTracker is an open source, multi-platform music application for creating .MOD and .
Stella - Stella is a multi-platform Atari 2600 VCS emulator released under the GNU General Public License...
OpenMPT - OpenMPT is a popular tracker software for Windows.
jGameBase - jGameBase is a fully-featured retro-gaming emulator frontend and game database utility.
FamiStudio - FamiStudio is very simple music editor for the Nintendo Entertainment System or Famicom. It is designed to be easier to use than FamiTracker, but its feature set is also much more limited.
Steem Engine - Steem is an open source Atari STE emulator for Windows and Linux.