Unicorn - Rack HTTP server for fast clients and Unix

Unicorn is an HTTP server for Rack applications designed to only serve fast clients on low-latency, high-bandwidth connections and take advantage of features in Unix/Unix-like kernels. Load balancing is done entirely by the operating system kernel. Requests never pile up behind a busy worker process. Does not care if your application is thread-safe or not, workers all run within their own isolated address space and only serve one client at a time for maximum robustness.