Karos Graveyard - Contains documentation, a scripting reference, and modification tutorials. - http://hw2.tproc.org/wiki/karosgraveyard/
Turanic Raiders Mod - Allows playing of the Turanic Raiders in multiplayer, also adds some never before seen ships - http://www.strategyplanet.com/piratesmod/
Homeworld Extreme - An ambitious project to tweak the HW .EXE - http://www.strategyplanet.com/homeworld/hwex/
Star Trek: Homeworld - Actually several mods, based on different Star Trek series - http://www.strategyplanet.com/homeworld/stvsw/sth/
Fleet Action: A Wing Commander Tribute - Total Conversion based on the Wing Commander series of games - http://www.strategyplanet.com/homeworld/fleetaction/
Star Trek: Fleet Academy - A popular modification for Homeworld that allows you to play using Star Wars ships. - http://www.strategyplanet.com/homeworld/zeelich/