This is JAP, which stands for: JAP is A Patcher. It's a memory patcher for the game, Mabinogi, and uses a slightly modified version of spr33's MemoryPatcher class.
This is licensed under the LGPLv3. This basically means that whoever gets this patcher, must also have access to the source. This does not mean that you cannot create a personal or private patcher. It is just whoever receives your version of the patcher needs to also have easy access to the source. I do not need to know you made one and nor does anyone else.
This patcher is different in a few ways from the other patchers out there apart from it being open source:
Unfortunately, there is no documentation of how to write the XML patches so the only way to write new patches is to learn from the existing patches or dig through the source of the program that generates the C++ files from the XML. It would be a great help if someone can create this documentation though
Remember to report bugs! Feature requests are always welcome, and so are extra developers ;)