SCARM - Simple Computer Aided Railway Modeller
Amper Music - Artificial intelligence music composer
TrainCad - Freeware Microsoft Windows program for designing model railroad layouts using standard tracks.
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
AnyRail - AnyRail makes model railroad design so easy, it's fun!
WaveBots Editor - Procedural music and sound maker that exports to Wav, MIDI, GoatTracker and much more.