HAProxy

HAProxy is a free reverse proxy offering load balancing, high availability and proxying for applications that use TCP or HTTP. It sits in front of servers, spreads incoming traffic between them and keeps services reachable when individual backends fail.

Repository topics point to features such as HTTP/2, TLS 1.3, caching, FastCGI, IPv6, the PROXY protocol and DDoS mitigation. The documentation is split across several files, including an introduction, a configuration manual, a Lua reference, notes on the SPOE engine, network namespaces under Linux, a management guide, the peers protocol and a regression testing suite, plus a wiki. Load generation utilities are described in separate documents.

HAProxy is written in C, and the repository is the development branch mirrored from git.haproxy.org. The project explains its life cycle in a BRANCHES file so you can choose the right version, offers a Discourse forum, mailing list, Slack and IRC for help, and reserves the issue tracker for bugs and feature requests.