Apache Software Foundation
What is it?
The Apache Software Foundation acts as an umbrella foundation for a large number of open source projects, providing infrastructure, legal protection, and further support. Some of its most popular projects include the Apache HTTP server, CouchDB (a document-oriented NoSQL database), and subversion (a version control system).
How to support
The ASF maintains a dedicated donation page, explaining in detail how to donate and how your donations will be used. Donation options include PayPal, Amazon Payments, Bitcoin or even your old car. The Apache Software Foundation is a registered non-profit, charitable organization under Section 501(c)(3) of the US Internal Revenue Code, so donations should be tax-deductible for residents of the United States.