When common things are easy and rare things are possible
Xtext is a framework/tool for development of external textual DSLs. Just describe your very own DSL using Xtext's simple EBNF grammar language and the generator will create a parser, an AST-meta model (implemented in EMF) as well as a full-featured Eclipse Text Editor from that.
The Framework integrates with technology from Eclipse Modeling such as EMF, GMF, M2T and parts of EMFT. Development with Xtext is optimized for short turn-arounds, so that adding new features to an existing DSL can be done in seconds. Still with the new version more sophisticated programming languages can be implemented.
Language development has never been so easy.
Confused about different versions of Xtext?
The first version of Xtext (we call it oAW Xtext) has been developed under the umbrella of openArchitectureWare. It's part of the 4.3 release.
Since the creation of TMF (Textual Modeling Framework), a sub-project under the eclipse modeling project (EMP), there is a new version of Xtext being developed. We refer to this version as TMF Xtext.
TMF Xtext will not be 100% compatible with languages developed with oAW Xtext but we'll provide migration help (partly automatically, partly via documentation).