Silverlight Documentation Refresh
The documentation for a published product periodically receives corrections and bug fixes in a refresh update that publishes many of the changes at once. On occasion there may even be new content added that was produced since the last release.
Silverlight 3 recently had a documentation refresh to fix bugs, but what I noticed first was that an offline documentation collection was being kept in sync with the changes to the MSDN documentation. I like having an offline copy of the documentation because of the speed and responsiveness when browsing through the documentation locally.
Here's the documentation collection for Silverlight 3 compiled into a help file if you also like having access to documentation offline.