XtremeWorlds
XtremeWorlds (XW) is a powerful, free 2D MMORPG maker. With XW you can make your own MMORPG with no coding in just minutes. If you find that the maker does not seem to have everything you need, you can code it in with our versatile scripting system. Unlike other free MMORPG creation systems, XW is updated regularly, so any bugs that are found are fixed immediately. XW has some great features, so please go check them out on the features page.
XW is still under active development. The latest build ships with a rewritten networking core, a live map editor and a hot-reloading scripting runtime.
Map Editor
Layered tilemaps, collision, lighting and NPC placement with live preview.
Scripting
A server-side script editor that uses script files to do tasks such as colors and game AI.
Netcode
Authoritative server with support for hundreds of concurrent players.