From the ALSA wiki
Alsa-oss is a package that uses a different means of providing OSS emulation (the other being the kernel level OSS emu, see the OSSEmulation page). It is done via a userspace lib that tweaks the open(), write(), etc.., system calls to do the right thing [tm]. See aoss page for usage details. Sadly it does not work with programs that use libc's fopen() and friends (changed in cvs, will update this page when in release)..
Fetch it from: