From Second Life Wiki
Currently working on:
Particles can be used to create great effects at a relatively low cost (rendering particles is easy for your graphics card). Unfortunately quite a few bugs have crept in after the rewrite that came in 126.96.36.199 . All of my currently submitted patches have been accepted by Linden Labs and should appear in a Release Candidate soon. This should bring particle possibilities to their best level yet (beating pre-188.8.131.52 too).
Currently on hold:
Performance profiling of Second Life viewer
I profile the Second Life viewer using AMD's CodeAnalyst. Once I've identified hotspots I check whether these can be improved in order to gain more performance. As particles eat a lot of CPU I'm profiling that particular area still while fixing all the particle bugs I can find.
Sculpted prim technical documentation
Current Wiki page seems to be sufficient for now.
Sculpted prim source code patching
Not trying anything before lossless compression has been introduced for sculpt textures
Patches applied internally by LL, awaiting appearance in an RC: