The idea is to use to keep Apple from being "locked into the browser plug-ins for...one particular standard."
What is SproutCore? From the SproutCore Web site:
SproutCore gives Apple a way to enrich its Web experience without locking itself into any other vendor's technology, as the SproutCore site notes:
Undergirding the move is the irony of Apple looking for ways to reduce proprietary lock-in...even while it locks its own customers into its platform. But that's another post.