The first change we’re making to TypeScript is that we’ve been taking a good, hard look at the compiler performance we had with 1.0. We knew we could leverage the experience from building the original compiler over the last two years. This led to experimenting with a new, lighter-weight compiler core. The early results with this new compiler core were so positive that we’re now focused on growing this core into the new TypeScript compiler and language service.
The first stage of this effort is to build a complete standalone compiler based on this new core architecture. The new compiler follows the same TypeScript 1.0 language spec, has the same compiler flags and compiler functionality, and outputs nearly identical code to the currently shipping TypeScript compiler. Once complete, the new compiler should be drop-in compatible with the existing one. The goal here isn’t new compiler features, but rather a cleaner compiler architecture that has better performance and allows us to add new features with greater ease in releases to come.
We’ve heard your feedback, and we’re making the move to GitHub. We’re continually looking for ways to improve how TypeScript works with the community, and we’re excited about what the move to GitHub could help us do in the coming months.