The ZIP module.
There are also specific info for the implementation for Saxon.
One of the main use cases is creating EPUB files. So the Zip module must support creating files described in the IDPF's OEBPS Container Format (OCF) 1.0. In particular, look at the section 4 ZIP Container.
If you want to help for the ZIP modules, here are some ideas got from the following email:
Some random tasks that need to be done:
- writing some documentation and examples. The wiki seems to be a good place to have rapidly something useful; it can be just writing down what you find out when you use the module functions or when you ask for help on the mailing list;
- write a first draft of the module. In my humble opinion, this is the next step to do. That means describing the module at a glance, each of its functions, their parameters and their side-effects, etc. There are also a few remarks on the mailing list we should take into account;
- writing a test suite. I think this is very important, but at the same time I guess that should be done after a first spec draft, even if that could be done before;
- writing and/or maintaining an implementation, or trying to convince the vendor of your processor to do so ;-)
If you want to pick one of them, just give it a try, and let us know what you did. If you need write access to the wiki, please tell me in private. If you want more info about the technical aspects of writing a draft, tell me and I will send you the stylesheets and I will help you to set your tools up.