Eureka

Eureka is a cross-platform Doom level editor (using FLTK widget library). It is based upon Yadex and is maintained by Andrew Apted. It provides a new interface, support for source ports, such as Boom, EDGE, Doom Legacy and Odamex and a 3D preview feature. Eureka is the only actively-maintained level editor for Linux, as development of the original Yadex ended in 2003 and the most recent official patches were from 2005.