If you want to contribute, please first submit a patch for a project you are interested in to me, either by email to markus.mottl@gmail.com or by providing access to your own Mercurial-repository of this project. If it seems like a useful contribution, I will then create a development branch for you on this server that you can write to from the outside (if required). I will merge this branch into the release branch from time to time as necessary.
Here is an example showing you how to check out source trees using Mercurial (read-only always works for everybody):
# hg clone https://hg.ocaml.info/release/lacaml
This will clone the LACAML-project to your filesystem. Using HTTP as transfer protocol should also work, but you should use HTTPS in case you need write access. After cloning you can pull changes if new releases are made. See the Mercurial-documentation for more information on using distributed version control.
Once you have write access to a repository, pushing or any other attempts to change the repository through Mercurial should work, too, though you will be prompted for authentication. You will receive your login information from me once your repository is set up.