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how_to_contribute.md

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 # How to contribute?
 
+XO is an Open Source project released under the [AGPL v3](http://www.gnu.org/licenses/agpl-3.0-standalone.html) license, contributions are therefore very welcome.
+
+## Bug reports
+
+Xen Orchestra has three bugtrackers:
+
+* [one for the server](https://github.com/vatesfr/xo-server/issues);
+* [one for the interface](https://github.com/vatesfr/xo-web/issues);
+* [and the last one](https://github.com/vatesfr/xo/issues) for common issues or when you don't know to which part it is related to.
+
+Feel free to report issues or features you miss.
+
+## Documentation / Code
+
+Using GitHub fork/pull-request feature, you may send us some fixes or enhancements.
+
+Please, do explain:
+* what you are fixing (issue number if available);
+* how you did it.
+
+### Pull requests
+
+The best way to propose a change on the documentation or the code is
+to create a [GitHub pull request](https://help.github.com/articles/using-pull-requests/).
+
+> Your pull request should always been against the `next-release`
+> branch and not against `master` which is the stable branch!
+
+
+1. Create a branch for your work
+2. Create a pull request for this branch against the `next-release` branch
+3. Push into the branch until the pull request is ready to merge
+4. Avoid unnecessary merges: keep you branch up to date by regularly rebasing `git rebase origin/next-release`
+5. When ready to merge, clean up the history (reorder commits, squash some of them together, rephrase messages): `git rebase -i`
+
+### Issue triage
+
+#### Labels
+
+**Type**
+
+- bug
+- cleanup: should be taken care of to avoid technical debt
+- enhancement
+- meta: points to other issues and is used to manage long term goals (similar but orthogonal to milestones)
+- question
+
+> All issues MUST have one of this label!
+
+**Difficulty**
+
+> This helps new people to contribute.
+
+1. easy
+2. medium
+
+**Component**
+
+- backup
+- GUI
+- upstream: not a XO issue → link to the upstream issue and monitor progress
+
+**Severity**
+
+1. low: will be fixed when possible
+2. medium
+3. high: should be fixed for the next release
+4. critical: should be fixed ASAP and a patch release is done once fixed
+
+> A new version MUST NOT be released with a `high` or `critical`
+> issue.
+
+**Status**
+
+For all issues:
+
+- duplicate: issue is a duplicate → SHOULD be closed
+- in progress: issue has been assigned and some work is going on
+
+> For now there is also the `fixed in next-release` label which
+> indicates this issue is resolved in `next-release` and will be
+> closed when merged on `master`.
+>
+> This label will no longer be necessary once the branch
+> reorganization (#69).
+
+For bugs:
+
+- confirmed: bug is confirmed → SHOULD be assigned to someone
+- invalid: bug cannot be confirmed → SHOULD be closed
+
+For enhancements:
+
+- draft: proposal is not finished and work should not be started yet
+- wontfix: not a real enhancement → SHOULD be closed