The Mana World (TMW) is a serious effort to create an innovative free and open source MMORPG. TMW uses 2D graphics and aims to create a large and diverse interactive world.
The packages you will need are all on this server. Get tmw-0.0.26.pet, physfs-1.0.1.pet and guichan-0.8.1.pet. You may also need libSDL_full.pet if you don't already have SDL installed. When you start the game it will download some other files. You can register a character from in the game client.
NOTE: A newer version is now available, see the next page of this thread.