Sentry is a realtime event logging and aggregation platform. At its core it specializes in monitoring errors and extracting all the information needed to do a proper post-mortem without any of the hassle of the standard user feedback loop.
Milestones releases are 1.3 or 1.4, and our deprecation policy is to a two version step. For example, a feature will be deprecated in 1.3, and completely removed in 1.4.