Vtgrep stands for Visual Tree Grep and is a GUI to tgrep. It allows the user to build graphical representations of tree structures and then translates them into the tgrep syntax. provides search functionality, as well as search and result logging.
cfgrep is an attempt to produce a grep-like program that uses regular expressions extended to describe context-free grammars. The largest part of the project is the C++ library developed to process those expressions.