Sfxr is a program that specializes in making chiptune sound effects for video games. Its interface consists of sliders that change the shape of the wave as well as the envelope and pitch. It has the ability to export to WAV for use in other programs.Discontinued
The last update was in 2012.
rFXGen is a simple and easy-to-use fx sounds generator, based on the amazing SFXR. Sounds could be saved as .rfx (sound generation parameters) and also exported to .wav as sample data, defining sample formatting.
This app is a random midi melody generator which you can use to create melodies. The melodies are procedurally generated and are royalty free. You are free to download the midi files and use them in your own music.
Industrializer is a program for generating percussion sounds for musical purposes. This program is great for generating new techno and industrial sounds. It also can produce chimes, bubbles, gongs, hammer hits on different materials and so on.
wafxr is a sound effect generator in the tradition of as3fxr, bfxr, jfxr, and others. But where such tools normally generate static files, this one plays sounds dynamically via Web Audio. Supports oscillators, FM synth, tremolo/vibrato, and various other filters and effects.