Zalando, a large online fashion plaform, published it's guidelines around open source creation and usage.

Why Open Source? Because it can: improve quality, mitigate risk, increase trust, save us money, expand our technology choices, be fun, enable us to give back to the community, strengthen our tech brand, and attract talent. ... Do “Open Source First”: If your Zalando project can also be useful to non-Zalandos, release it as open source from the start.

https://github.com/zalando/zalando-howto-open-source