Aegis.jar -

: A subsystem used in Java web services to map Java objects to XML without requiring extensive annotations.

: A project change supervisor used in UNIX environments for software development and source control. Are you setting this up for a Minecraft server , or Aegis (2.1) - Apache CXF Aegis.jar

Depending on your field, "Aegis" may refer to different software components: : A subsystem used in Java web services