Open Source Initiative

What is it?

As stated on their website:

We are the stewards of the Open Source Definition (OSD) and the community-recognized body for reviewing and approving licenses as OSD-conformant.

How to support

The Open Source Initiative takes donations in several ways, including Flattr. You can also join as a member. For people who pay taxes in the US, it is of interest that OSI is a 501(c)(3) deductible organization.

Why support?

The OSI supports open source in so many different ways that it's hard to summarize: They educate, promote and support open source and open source projects.