You’re in search of Audio API for your game and you found that most of the API are windows only. Commercial API offers cross-platform capability but at cost which you can’t afford. Now what to do? Take a look at Audiere if it suits your project.
What is audiere?
Audiere is a high level audio API. It supports mp3, flac, wav, aiff, ogg vorbis, xm, mod and it file formats. On windows it supports WINMM, DirectSound, and on linux it supports OSS.
Where to get it?
Audiere is available for download here .
Is it portable?
Yes. It Works with Windows and Linux.
What about license?
Audiere is open source and available under LGPL license.
Where to go for documentation?
It is available in multiple formats. here.