This version of the Viewer uses a less complex file caching system to save local copies of frequently used assets such as meshes, sounds and animations.
There should be no user facing differences and your Second Life experience should be identical to other versions.
Resolved Issues
SL-15551 Cache is trimmed according to cache size when viewer was started, not current cache size.
SL-15547 Viewer hung while looking for a file in cache
SL-15398 Include Pull Request from FS:Ansariel for "Change all remaining boost::filesystem methods to their non-throwing overloads"