A wiki page went up Today (4/8) : Release Notes – Second Life Project Materials – 3.5.1.
Warning: DO NOT use this viewer to edit objects you want to keep. This version of the Project Viewer is an Alpha version. It may BREAK anything you edit with it.
You have been warned.
All of the main grid is Materials enabled. The ADITI preview grid’s recently updated regions are Materials Enabled. Older regions are not. There is no easy way to tell for sure.
The code repository is named: viewer-development-materials. This code is NOT ready to be merged to other viewer projects. Oz Linden says they have yet to stabilize the code. That means depending on the problems they find there may or may not be significant changes and re-writes.
The viewer can be downloaded from the Alternative Viewers Page.
More information to come.