This is an open Source extension library for the Adobe Flash Player that enables support for otherwise unsupported sound systems. It provides the libflashsupport.so plugin. The sound system to use is automatically detected:

* It first tries to detect Esound,
* Next, it checks for OSS.
If all of the above failed, it falls back to the ALSA driver that's built directly into FlashPlayer 9.

For PulseAudio support, look elsewhere.