I started this after my first homebrew, a shoot'em up written in C++. In this homebrew, each IA was written in the C++ code. I found that borring, and I thought about a scripting language for that. There were Lua, but I just don't like it. The language I wanted to use was Ruby. I type "Ruby PSP" in Google, found a patch, used it, and read a tutorial about the API. It was really easy, and I wrapped a class I took from the other game with it.
Now, I'm not trying to add a scripting system to my homebrew. I'm writing a Ruby interpreter, just as there were ( and are, of course ) for Lua and Python. The name, "Joyau", is the french ( It's my mother language ;) ) for "Jewel".
Since I managed to run Ruby, I had to have another objective. I want Joyau to be easy to use, and to implement multiple things. ( Yeah, there is a built-in animation system, and the tiling system is there too )
Its source code is released under the GPL licence. Even if it's possible that no one ever modify it, I want those who modifiy it to publiy their changes. Notice this only applies for the C++ part. I let you use the Ruby samples without any restrictions - anyway, you'll have to show your script if you release your version...
I wrote a full documentation in the wiki. Just give a look at it if you want a list of features. If you want to use it, there are a lot of samples which shows how to use almost everything. ( when I add a feature, I test it, and commit my test as a sample )
At each merge ( git ;) ), I publy two binary packages. An EBOOT, of course, but a PRX too. The PRX is there because it can be usefull to run Joyau from psplink... Well, it's usefull for me, and it can be usefull for others too ;)
The project home page, on github : http://github.com/Kode/Joyau/tree/master ( I can't put URL... )
( The "download" icon is a tarball of the source code. You'll have to compile it by yourself. You should use the "downloads" tab if you want to use Joyau... and a git clone if you want the source code )