HTTP Kit

http-kit is a minimalist, event-driven, high-performance Clojure HTTP server/client library with WebSocket and asynchronous support. A simple, high-performance event-driven HTTP client+server for Clojure. HTTP Kit is an (almost) drop-in replacement for the standard Ring Jetty adapter. So you can use it with all your current libraries (e.g. Compojure) and middleware. Using an event-driven architecture like Nginx, HTTP-kit is very, very fast. It comfortably handles tens of thousands of requests/sec on even midrange hardware. Here is another test about how it stacks up with others. It's not only fast, but efficient! Each connection costs nothing but a few kB of memory. RAM usage grows O(n) with connections. Written from the ground-up to be lean, the entire client/server is available as a single ~90kB JAR with zero dependencies and ~3k lines of (mostly Java) code. Synchronous is simple. Asynchronous is fast & flexible.