DD-WRT
Open Source
DD-WRT is free Linux-based firmware for several wireless routers, most notably the Linksys WRT54G.
Tomato
Free
Tomato is a small, lean and simple replacement firmware for Linksys' WRT54G/GL/GS, Buffalo WHR-G54S/WHR-HP-G54 and other Broadcom-based routers.
OpenWrt
Open Source
OpenWrt is an embedded operating system based on Linux, primarily used on embedded devices to route network traffic.
Compare MikroTik RouterOS with alternatives
Compare DD-WRT and MikroTik RouterOS and decide which is most suitable for you.
Compare OpenWrt and MikroTik RouterOS and decide which is most suitable for you.
Compare Tomato and MikroTik RouterOS and decide which is most suitable for you.