What does this really mean?

First of all, we work together to achieve the visions of Apache Zest™, based on technical merits alone in an open and friendly manner, mostly via the dev@zest.apache.org mailing list. It means that everyone in the community are stake holders in the resulting codebase, and noone can claim it is mine.

Secondly, all source code, artwork and documentation produced in Apache Zest™ are licensed very liberally under the Apache License ver 2.0. This allows you to use our efforts in your own projects, whether they are open sourced, commercial or any other arrangement you like, subject to a few terms like "Must re-distribute a Notice that your product contains Apache Zest™ and such. See the License text for exact details, and please consult with IP rights lawyers about this and other Open Source licenses.

Thirdly, Apache Zest™ invites everyone to participate. There are many ways to participate, not only by writing code. See list in the Participation section.