As you know the Materials System has been released by the Lab. The third party viewers are picking up the project and adding it to their viewers. Cool VL Viewer and Niran’s Black Dragon have Materials. Firestorm 4.4.1 does not have Materials yet but, 4.4.2 is nearing release and will have materials.
There are fixes for problems in Materials System that are in the pipeline. One of those has to do with Ambient Occlusion on large objects. That is unlikely to be in Firestorm’s 4.4.2 release.
SSA
Server Side Appearance (SSA baking) is planned for the release the week of July 7-13. The Lab is expecting it may be on the 8th or 9th.
Firestorm and Phoenix users will see a huge notice on the viewer’s splash screen that they need to update. If you have not yet updated to 4.4.1, avoid the rush and do it now.

