Agree. I've done several of these, for example I worked as a contractor at an investment bank where the team I was on developed the Apache Qpid message broker.

Agree. I've done several of these, for example I worked as a contractor at an investment bank where the team I was on developed the Apache Qpid message broker. This was full-time work on an ASF project, and how I got my first commit bit in an open source project. Currently, the company I work for produced an open source project that they donated to the ASF as an Apache project, which I work on full time, as well as contributing to various other open source projects we use as dependencies or are part of the ecosystem. I ended up founding another open source project inside the company, that has now become part of our project line. To make a living developing open source software, this is probably the best/easiest way, and is certainly incredibly rewarding.