OSS Proxy Daemon is a Linux userland OSS sound device (/dev/[a]dsp and /dev/mixer) implementation using CUSE. Currently it supports forwarding OSS sound streams to PulseAudio and ALSA.

Actually emulating the OSS devices makes for a more robust emulation compared to OSS wrappers using LD_PRELOAD, like aoss and padsp. It also works better when running foreign-architecture applications or using old libc versions for compatibility reasons.