Together with Daniel Höller I'm the main developer of the HTN planning system PANDA. There are currently two versions of PANDA which are maintained:

• PANDA3 an implementation in Java and Scala that was used in PANDA's most recent evaluation. Executables, its source code, and instances are available.
• pandaPI an implementation in C++. It is currently under development. The parser, the grounder, and the are search engine publicly available.