EMF is an essential piece of many Eclipse-based modeling projects. It does a very good job of providing abstract syntax for models. However, there was little support at the level of concrete syntax, i.e. concrete notations to describe models, at least until GMF entered the stage.
There are several ways of displaying and editing models. The two primary alternatives are graphical (or visual) concrete syntaxes and textual notations. EMP already has a solution to efficiently develop editors for graphical notations, namely GMF. However, in many situations, textual representations are much better suited. Therefore, the proposed TMF project will provide a means to efficiently create editors for custom textual notations.
While graphical notations are often useful to describe structural concepts (e.g. class diagrams), textual notations are often a better fit for describing behavior or algorithms (e.g. expressions). Another advantage that textual representations have over graphical notations is that expert users often find them faster and easier to modify, and that there is a rich set of existing tooling for dealing with text files (diff, merge, copy & paste, search & replace ...).