AEGIS is Windows Server software used along with Microsoft SQL Server by Gravity Corporation to run the official Ragnarok Online game servers. It was originally developed for exclusive use within Gravity and Gravity subsidiaries, but has been leaked within its lifetime, purportedly by several teams who compromised official computers which contained AEGIS binaries.
AEGIS consists of a number of components, an Inter Server (responsible for Guild Siege, Guild Chat, Private Message and synchronization between servers), a Zone Server (responsible for Game Play Dynamics), a Character Server (responsible for Character Information), and an Account Server (responsible for verifying information in account database, such as if it exists, if it is either paid for or not (active/inactive), etc.).
AEGIS was originally created by Hakkyu Kim (Neolith) and was his first server project. Despite the fact that Aegis is referred to as production quality (due to the involvement of commercial organizations) leaked versions revealed that the majority of its configuration files were very simple, it used very inefficient means of storing information for reference, and showed very high memory usage when there were no routines running to suggest such usage.
The original development team was forced to leave the company after a takeover by Samsung Electronics and most of the core members are now working on a new project known as Granado Espada.