Jnario is a new language for testing Java applications. Jnario takes the ideas of Cucumber and RSpec from the Ruby world to the Java world. At the same time, Jnario preserves the things we Java developers like so much: type safety and great tool support!
You can also write executable acceptance specifications similiar to Cucumber, but with less maintenance overhead.
I was always a big fan of Taskpaper, a todo app for OS X, with a super simple and readable syntax. To be able to use it also under windows and linux, I created a clone based on Eclipse.
During my time at BMW Car IT I was the development lead of ARText, a textual language framework for AUTOSAR. However, I am no longer involved in ARText.
Xgherkin is an Eclipse editor for Cucumber's feature definition language. This was one of my first tries, to see whether it is possible to use Xtext to define DSLs with support for free text.
Xrepl was an experiment to see whether it is possible to create an interactive programming environment for Xbase. Xbase is the extensible expression language provided by Xtext.