For awhile now, the SL viewer has been using some depreciated OpenGL calls, which is a fancy way of saying it was using old methods to talk to the video card. Well, recently, those old methods were removed from the more up-to-date video cards and video card drivers, causing many people issues with functionality and stability.
Linden Lab started a drive to eliminate the use of those old, depreciated functions from the viewer, which they documented in this JIRA. As you may notice, the JIRA has been marked as “resolved”, meaning the bulk of this work has been completed. The new code hasn’t been officially released yet, but you can give it a try even now if you want an early look.
Chalice Yao released a revision of her NaCl viewer today, which contains this new OpenGL code, as well as adding RLVa. So if you are the adventurous sort, give it a try. But be warned, it’s possible a bug is lurking (you never know).
For voice support copy the slvoice.exe and vivox*.dll files from an official viewer to the NaCl directory.
I can say personally I love this viewer and it works beautifully. I even went from 25 fps to 78 fps (!!!) with shadows enabled. If this is any indication of what the new OpenGL code can achieve, it’s a great day for SL indeed.