The source of GitLab Community Edition is [hosted on GitLab.com](https://gitlab.com/gitlab-org/gitlab-ce/) and there are mirrors to make [contributing](CONTRIBUTING.md) as easy as possible.
- GitLab Community Edition (CE) is available freely under the MIT Expat license.
- GitLab Enterprise Edition (EE) includes [extra features](https://about.gitlab.com/features/#compare) that are more useful for organizations with more than 100 users. To use EE and get official support please [become a subscriber](https://about.gitlab.com/pricing/).
Included with the GitLab Omnibus Packages is [GitLab CI](https://about.gitlab.com/gitlab-ci/) that can easily build, test and deploy code.
Please see the [requirements documentation](doc/install/requirements.md) for system requirements and more information about the supported operating systems.
There are various other options to install GitLab, please refer to the [installation page on the GitLab website](https://about.gitlab.com/installation/) for more information.
To work on GitLab itself, we recommend setting up your development environment with [the GitLab Development Kit](https://gitlab.com/gitlab-org/gitlab-development-kit).
If you do not use the GitLab Development Kit you need to install and setup all the dependencies yourself, this is a lot of work and error prone.
One small thing you also have to do when installing it yourself is to copy the example development unicorn configuration file:
Instructions on how to start GitLab and how to run the tests can be found in the [development section of the GitLab Development Kit](https://gitlab.com/gitlab-org/gitlab-development-kit#development).
## Software stack
GitLab is a Ruby on Rails application that runs on the following software:
- Ubuntu/Debian/CentOS/RHEL
- Ruby (MRI) 2.0 or 2.1
- Git 1.7.10+
- Redis 2.0+
- MySQL or PostgreSQL
For more information please see the [architecture documentation](http://doc.gitlab.com/ce/development/architecture.html).
There are a lot of [third-party applications integrating with GitLab](https://about.gitlab.com/applications/). These include GUI Git clients, mobile applications and API wrappers for various languages.
Since 2011 a minor or major version of GitLab is released on the 22nd of every month. Patch and security releases are published when needed. New features are detailed on the [blog](https://about.gitlab.com/blog/) and in the [changelog](CHANGELOG). For more information about the release process see the [release documentation](https://gitlab.com/gitlab-org/gitlab-ce/tree/master/doc/release). Features that will likely be in the next releases can be found on the [feature request forum](http://feedback.gitlab.com/forums/176466-general) with the status [started](http://feedback.gitlab.com/forums/176466-general/status/796456) and [completed](http://feedback.gitlab.com/forums/176466-general/status/796457).