CoderBuddy is free for commercial, non-commercial and open source projects.
There were a few posts on HN about having a web-based way to use Google App Engine for static sites, and that's one thing you can do with CoderBuddy.
You can build and publish web-based applications in Python on Google App Engine. CoderBuddy comes with an instantly updating test environment and integrated publishing to App Engine. we're starting to roll out a more advanced editor, the 'New Editor (beta)' link with tabs.
We invite your suggestions of who we should test this out with, and your top 3 feature requests. We've tried to make it really easy for someone to get started coding and publishing. We'd also love to hear from folks giving workshops soon who might want to try this out there.
Thanks, -Adrian (Napster founding investor, founder of social networking pioneer Ryze)