https://github.com/i-rinat/apulse

It is compatible with Firefox 52.x and Skype.

Since PulseAudio creates an alsa-style interface, does apulse run under PulseAudio?

(There may not be a practical use for this, but it could be a way to test both PulseAudio and apulse.)

What's use for this?... Modern cards do not have hardware mixing and Pulse is best software mixer. I have SBLive and still prefer Pulse for ability to mix and route signals over Bluetooth/wireless with mouse clicks.

Could possibly be of some use for OSS users to run software that uses Pulse, bypassing the mixing - but that is not goal of it, since it relies on simple, feature-limited "dmix" - which itself should be deprecated long ago.

The documentation says "As aoss was a compatibility layer between OSS programs and ALSA", but aoss is very primitive and currently the proper OSS support for Pulse is provided with "osspd".

edit: its "osspd", oss proxy daemon.

No.
apulse provides very simple PulseAudio API so those software that (only) work on PulseAudio, could also run and produce sound on ALSA.

Official build of Firefox 52.x disabled ALSA. Use apulse will make it work again on ALSA. PulseAudio is the worst mixer, ever.

Well, interesting. Not entirely sure if I'll have any use for this, but I tried it and it seems to work. Never heard of this project before.

Is this to be seen as proof of your competence? Tell me, are you also using bsdinit?