Software repositories, or repos, are storage locations for software, whether completed packages or code in development. Having a designated central location for software makes it easier for team members to access the code for development and referral. It can also be a location for end users to access the software.

Many software developers provide multiple versions of software, from nightly builds generated by a build server to various versions of the final product. Documentation is frequently included as well, often as separate files for downloading but sometimes as online HTML files.

For Python, the online PyPI repo is used for third-party Python modules; these are most commonly installed through the pip command. Another common option is to post packages onto GitHub; many packages available on PyPI have a hosting on GitHub as well.

GitHub is one of the most popular sites for open-source software, though Bitbucket, Gitlab, and other sites are available. That's not counting internal development repos for companies and organizations.

Software repositories often include, or provide extension support to, common build tools, such as CI build servers, documentation generators, automated testing suites, and so on. Often, these tools can be connected to a programmer's integrated development environment (IDE), such as PyCharm, allowing the programmer to rarely have to leave the IDE to use a tool.