bfxr is not available for Linux but there are some alternatives that runs on Linux with similar functionality. The best Linux alternative is sfxia, which is free. If that doesn't suit you, our users have ranked more than 10 alternatives to bfxr and five of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to bfxr are rFXGen (Freemium, Open Source), Power Station Industrializer (Free, Open Source), Explodomatica (Free, Open Source) and Melody Generator (Free).
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.
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.
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.