I volunteer as an editor for the Mozilla Developer Network (MDN), an organization that creates free open source software such as the Firefox browser. MDN has a large number of technical topics awaiting review, around 625 at this moment.
Most topics are very short and well-written, so they require few if any edits. Other topics are long and written by smart people who aren't great at technical writing. Very few topics are poorly written. The scope, pace, and choice of topics to edit are up to the editor. The style guidelines are not stringent. So far, I haven't come across any interactive examples that need testing.
I enjoy editing, and I find contributing to open source software gratifying. It also improves my writing/editing skills, and I gain technical knowledge. However, there aren't a lot of extrinsic rewards, such as earning reputation points.
People who volunteer do this have to be mostly content to work quietly in the background. Do you have any suggestions on how to attract and retain like-minded technical editors?