Microsoft yesterday announced that they are developing a new original compiler over the last two years and the early results with this new compiler core were so positive that they are now planning to grow this core into the new TypeScript compiler and language service. The good news is that 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. Microsoft said that when this development is complete, the new compiler should be drop-in compatible with the existing one. Microsoft believes that this new compiler has much cleaner compiler architecture that has better performance and allows them to add new features with greater ease in releases to come.
Our work to date on the new compiler has been very promising. At its current level of completeness, the new compiler is able to compile existing real-world TypeScript code 5x faster than the currently shipping compiler. These results are still early. Once the compiler has reached parity, we’ll be able to report out a more complete picture of the performance improvements.
Read more about it here.