L2J is an alternate game server for Lineage2. The L2 protocol is reimplemented in the server, so you can play with this server without any modifications to the client (except changing the server IP address). The latest USA live client version is always supported, so don't expect this server to work with the PTS/Korean client.
Mason is a game system being developed by WorldForge. The primary focus for Mason is to enable players to build a persistent world in-game. Players will be able to manipulate items by creating new items from raw materials, attaching existing items together, or splitting items into component parts. Complicated structures such as houses can be designed on paper as a blueprint and then built with suitable building blocks and skills.
ZapM is a sci-fi rogue-like game that borrows monsters and ideas from all over and crams them into a ridiculous and perilous space maze where even a toaster can kill you. But the intrepid hero, a badass space marine (or perhaps you're playing as a skilled software engineer, or a plucky quarterback, or a mutant psion?), has no choice but to enter this dangerous hulk and search for the legendary "Bizarro Orgasmatron", the only artifact that can save the universe from certain destruction!