Reason I ask is that there's a FOSS Visual Novel that I haven't seen mentioned on the forum or blog.
http://cameliagirls.com/
It's called @CameliaGirls, and it's an in-development VN written in Ren'Py. The source code and game content are released under the CC-BY-SA license. It features excellent original artwork and an entertaining, light-hearted story. I'm not part of the dev team, just a friend and fan of the devs sharing some of the love.
It's kind of short, since only the first act has been released so far. Even so, if you're interested in VNs, I definitely encourage you to check this one out. If you like it, please be sure to send some positive/constructive comments to the developers! The project has unfortunately stalled, but maybe some feedback from new players will help stimulate the project.