Various spin-offs of OpenWRT also exist, some with highly specific usage scenarios. The Cerowrt build, for instance, was created as part of the Bufferbloat project to address network bottlenecking issues in LANs and WANs. FreeWRT is even more developer-focused than the core OpenWRT builds, but has a handy Web-based image builder for those who want to create a FreeWRT firmware with a little guidance. And Gargoyle offers as one of its big features the ability to set bandwidth caps per host.
Limitations: The biggest strengths of OpenWRT are also its biggest limitations. It's best used by people who really, really know what they're doing. If you just want to replace your stock router firmware with something a little more current, steer clear.
Recommendation: OpenWRT is best suited for experts. This is the firmware for people who want as few limitations as possible on what they can do, are ambitious about using unusual hardware, and feel comfortable with the kind of tinkering that would normally go into rolling one's own personalized Linux distro.
M0n0wall and PfSense Among the other projects here, m0n0wall is closest in spirit to OpenWRT. It's a version of FreeBSD that works as a firewall or router, so it's much closer to a full-blown OS installation than a mere firmware layer.
Supported hardware: M0n0wall runs on embedded hardware systems with at least 64MB of RAM and 16MB of flash storage. It can also be run on commodity x86 PC hardware, and a high degree of compatibility is provided with common PC components thanks to the BSD driver library.