Basic

• The 10K problem – http://www.kegel.com/c10k.html

Libraries

• libevent – http://libevent.org/
• libev – http://software.schmorp.de/pkg/libev.html
• libuv – http://libuv.org/

References

• Lugdunum (edonkey server) – http://lugdunum.shortypower.org/kiten.html
• A Million-user Comet Application with Mochiweb – http://www.metabrew.com/article/a-million-user-comet-application-with-mochiweb-part-1
• 600k concurrent websocket connection on AWS using node.js – https://blog.jayway.com/2015/04/13/600k-concurrent-websocket-connections-on-aws-using-node-js/
• [Hacker News Discussion] 600k concurrent… – https://news.ycombinator.com/item?id=21222913