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. If you're interested in getting involved, we encourage you to join the OpenLiteSpeed Development Group on Google Groups.
- Minimal memory footprint.
- WebAdmin GUI with real-time statistics.
- Apache compatible rewrite engine.
- Worker processes for scalability. Ability to bind certain processes to particular workers.
- High-performance event-driven architecture using kqueue (FreeBSD and OS X), epoll (Linux), /dev/poll (Solaris), and poll.
- Can handle thousands of concurrent connections.
- Easy virtual host configuration via templates.
- Supports PHP, Ruby, Python, Perl, and Java external applications.
- LSAPI, a LiteSpeed-native SAPI, greatly improves PHP and Ruby speeds.
- Delegates external applications to separate processes, increasing efficiency.
- Buffers requests and responses to external applications to more efficiently serve multiple connections.
- Efficient CGI daemon.
- Compatibility with third party PHP accelerators.
- Apache compatible SSI support.
- SSL support and hardware acceleration.
- Bandwidth and connection throttling.
- IP-based access control.
- HTTP basic authentication.
- Referer limiting.
- Response rate limiting.
- Buffer overrun guards.
- Graceful restart feature allows application of configuration changes and upgrades without server downtime.
- Fault tolerance and instant restarting.
- Runs completely in user space. OS reliability is not affected.
- Accept-filters and TCP_DEFER_ACCEPT support.
- sendfile() support.
- Pipelined requests.
- Gzip compression for reduced bandwidth use.
- Chunked transfer encoding.
- Keep-alive connections.
- IPv4 and IPv6.
- Entity tags.
- Multi-range requests.
- Exact/prefix/regex-based matching.
- Name-based and IP-based virtual hosting.
- Custom error pages.
- Autoindexing.
- MP4 and F4V streaming.
- IP geolocation.
- Can send logging to logging server.
- Simple load balancing.
- XML or flat file configuration.
- Can serve as a reverse proxy to accelerate static content delivery, compress throughput, or run security.
- CentOS 5 and 6
- Ubuntu 8.04 and up
- Debian 4 and up
- OS X 10.3 and up
- FreeBSD 4.5 and up
OpenLiteSpeed Development Group on Google Groups
OpenLiteSpeed 1.0 press release
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 page caching. Users can find more about Enterprise Edition on the LiteSpeed Technologies homepage.