Simple, powerful and stable Firmware for LinkSys WRT54GL

Round up:

1. People love DD-WRT because it supports all kinds of cpus pretty well. It is sort of commercial. But the money aspect seems to keep them motivated.
2. People love OpenWRT because it is open and libre. Also it's more like running your own linux on a low-power box. It's got package-management even after it's up and running.
3. People love FreeWRT because it's got a more accessible configurable build system.
4. People love Tomato because it's red, has a nice interface, solid feature set, is straight forward, and can be caramelized for flavor.
5. People don't care about HyperWRT anymore because it's kind of old now.
6. People actually hate SveaSoft despite it being first (good read BTW).

I'm running Tomato on my WRT54GL and I love it. It doesn't quite have all the features of DD-WRT but it been rock-solid and still has all the essential features, of course including port forwarding. It has a nice AJAX interface that can show you your bandwidth usage, has good QoS controls, lets you control tons of aspects of your wireless (many types of security, antenna power, etc). I'd definitely recommend it.

http://www.dd-wrt.com/

You can see your router in the list of compatible routers at:

http://www.dd-wrt.com/dd-wrtv3/dd-wrt/hardware.html