I’m putting together a very simple newsletter system for a client, based on Rails. It’s meant to handle around 1000 addresses, and be simple to use: you create a newsletter with fckeditor, look at it, then send it if everything looks good. It also ads links so that people can unsubscribe, or subscribe from the site (with confirmation provided via a link in an email).
It’s not nearly as extensive as a lot of what I’ve seen out there in PHP, but I really needed something in Rails and didn’t find anything that worked for me. I’m considering open sourcing the code, but am only likely to do so if there is interest from people willing to work on the code. I’m just not in the mood to put code out there that just sits there. If you are interested, email me and we can work something out.