We are moving to use MIO which allows a huge amount of async connections in rust as opposed to the thread model we currently have. There will be some API changes but not too many. Andrew is spending time spec’ing the tasks and RFC’s for this move. If you check MIO you will see why this is happening. Also moving several modules out of crust to their own crate. Just more simplicity, reduced resource usage and significant performance improvements. atm Rust async IO is young and MIO makes great use of epoll etc. So we let the OS handle 10’s of thousands of messages per second as opposed to a more blocking threading module with a centralised state object.