Æsir is a software development project revolving around the creation of MMORPG game client, compatible with RAthena. It aims to provide the better game experience using a modern render engine and the freedom to modify the client. Due to having all the source code, it becomes possible to fix some bugs of the original client and also add new features, such as: Per-pixel lighting; Real-time shadows; Instant map loading; Native support of Windows, Linux, Mac OS X, An