goim
goim is a im server writen by golang
...Supports heartbeats (Application heartbeats, TCP, KeepAlive, HTTP long pulling). Supports authentication (Unauthenticated user can’t subscribe). Scalable architecture (Unlimited dynamic job and logic modules). You can view the comments in target/comet.toml,logic.toml,job.toml to understand the meaning of the config. Install comet/logic/job modules and use Supervisor management (You might need to change the configuration files based on your servers).