Two important parts of Zalando Technology's culture — our self-organized guilds, and our support for open source— intersect via our Open Source Guild. The Guild is an informal group of engineers and tech evangelists dedicated to strengthening our open source culture both internally and externally. Every two weeks, Guild members meet to brainstorm ideas for promoting our projects to the tech community; collaborate on internal policies related to licensing and other relevant topics, and trade insights and best practices.

One of the Guild's biggest projects of the past few months has been drafting a vision statement and set of "open source principles" to encourage everyone on our team to think in an "Open Source First" way. After much commenting, copy-tweaking and debate, here they are. Feel free to customize and adopt them for your own team's purposes:

Vision: We strongly believe that open source software benefits the tech community, and that providing broadly useful code to the world is a virtue. We strive to work in an open source way to the betterment of Zalando and the world.

• Do “Open Source First”: If your Zalando project can also be useful to non-Zalandos, release it as open source from the start.
• Take Ownership: Your team is responsible for ensuring that it’s possible to open source your project. Your delivery lead is available for guidance.
• Share Your Code: All code shared between teams must be open source.
• Be Safe: To ensure the broadest possible use of your project, use the MIT License only.
• Deliver Quality: Provide a great out-of-the-box experience.
• Provide Documentation: Include a clear README and default working configuration.
• Stay Secure: Make sure your project doesn’t include Zalando specifics, such as credentials and private identifiers.
• Ask for Help: Find colleagues to brainstorm ideas for your project and to review your work.
• Promote: Tell the world about your project via blog posts, social media and conference talks.
• Join the Open Source Guild: Help us make open source stronger at Zalando!

In true open source fashion, these principles remain a work in progress; we'll make revisions and updates here.