Qubes is split into a bunch of git repos. This are all contained in the `qubes-src` directory under qubes-builder.
The best way to write and contribute code is to create a git repo somewhere (e.g., github) for the repo you are interested in editing (e.g., `qubes-manager`, `core`, etc). To integrate your repo with the rest of Qubes, cd to the repo directory and add your repository as a remote in git
**Example:**
``` {.wiki}
$ cd qubes-builder/qubes-src/qubesmanager
$ git remote add abel git@github.com:abeluck/qubes-core.git
```
You can then proceed to easily develop in your own branches, pull in new commits from the dev branches, merge them, and eventually push to your own repo on github.
When you are ready to submit your changes to Qubes to be merged, push your changes, then create a signed git tag (using `git tag -s`). Finally, send a letter to the Qubes listserv describing the changes and including the link to your repository. Don't forget to include your public PGP key you use to sign your tags.
When developing it is convenient to be able to rapidly test changes. Assuming you're developing Qubes on Qubes, you should be working in a special VM for Qubes and occasionally you will want to transfer code or rpms back to dom0 for testing.
Here are some handy scripts Marek has shared to facilitate this.
