There was a time when PS was a one of the best polish tracker. Then they merge with HeavenTracker and we have HeavenSource tracker. But its looks like co-operation wasnt good and now old team of PS bring back to life PolishSource.org.
PS is general/0day tracker not only with polish content. You can find lots of english content too (scene and non-scene).
Currently there is open signup till 4000 members.
Registered users 543
Signup Link: Here
Thanks to Poldolski for info