Ptolemy is an extension of Java whose goal are to enable separation of crosscutting concerns, while retaining our ability to understand separated concerns modularly. It balances modularity and expressiveness for aspect-oriented software development.
JUndo is a declarative object-oriented programming language with functional, and intensional programming characteristics. Applications include multi-level undo and sophisticated error recovery. See http://verdantium.blogspot.com/
TreeDL (Tree Description Language) is a notation for tree structures used by programs (like syntax trees) and tool for translation of tree descriptions to target programming language, docs generation, etc. Tool's functionality can be extended by plugins.
ECCO is a web-based IDE. In other words is an online development environment with file manager, console interface for compiling and execution of code and an editor with syntax highlighting, tabs and support for many languages and accessed with a browser
Extended C gives Object-Oriented features such as self-referential structure pointers via macros to C, resulting in an object-oriented style. Currently tested in gcc, we hope to stabilize it for other compilers as well, including Borland & Visual Studio.