What Is OpenLiteSpeed?

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What Is OpenLiteSpeed?

OpenLiteSpeed is a high-performance, lightweight, open source HTTP server developed and copyrighted by LiteSpeed Technologies, Inc. Users are free to download, use, distribute, and modify OpenLiteSpeed and its source code in accordance with the precepts of the GPL version 3 license.


  • Event-driven architecture with extremely low resource (CPU and RAM) overhead.
  • Handles hundreds of thousands of concurrent connections without load spikes.
  • WebAdmin GUI with real-time statistics.
  • Rewrite engine uses Apache mod_rewrite syntax.
  • Worker processes for scalability. Ability to bind certain processes to particular workers.
  • High-performance coding using kqueue (FreeBSD and OS X), epoll (Linux), /dev/poll (Solaris), and poll.
  • High-performance page caching.
  • Support of third-party modules through API (LSIAPI).



We've begun to release a series of benchmarks comparing both editions of LiteSpeed with Apache 2.2, Apache 2.4, and nginx. We think you'll be pleasantly surprised.

Supported OSs

  • CentOS 5, 6 and 7
  • Ubuntu 8.04 and up
  • Debian 4 and up
  • Solaris(x86): Sun0S 5.8 and up
  • OS X 10.3 and up
  • FreeBSD 4.5 and up

How Do I Get Involved?


OpenLiteSpeed is available under two different licenses. Users willing to abide by the GPLv3 are welcome to download, use, distribute, and modify OpenLiteSpeed and its source code. Companies or individuals who wish to use OpenLiteSpeed in a proprietary product can contact LiteSpeed Technologies about obtaining an OEM license.

LiteSpeed Enterprise Edition provides some features above and beyond OpenLiteSpeed: hosting control panel compatibility, .htaccess file compatibility, mod_security compatibility, and ESI support. Users can find more about Enterprise Edition on the LiteSpeed Technologies homepage.