UPDATE (March, 2009): Greenfoot and its cousin BlueJ are now Free software!
Bill Kerr has an interesting post regarding the unfortunate status of Scratch licensing. Bill has reiterated his and others’ comments which get right to the heart of the matter. Worry over forking can be put to rest with licensing requiring derivative works to be clearly marked out so that they don’t infringe on an original work’s trademark.
This is an interesting example I hope the developers of Greenfoot consider closely. Not too long ago, I asked them why they restrict commercial use and “disassembly” of Greenfoot. Here are key excerpts from an email (June 2008) explaining their thoughts:
The [software] is closed because we want to avoid feature creep. [...] The major strength of [the software] is its simplicity and careful selection and integration of features. [...] We are providing a high level of user support. Our users are generally beginners. If the system were forked, we would have difficulty dealing with the forked version in a support context.
If the Greenfoot team wishes to avoid “feature creep” then they can simply refuse contributions to the official Greenfoot version. If the “major strength” of Greenfoot is simplicity and integration, then users will stick with the official Greenfoot release. If they don’t, giving students the freedom to go their own way with an unofficial release can’t cause harm. And finally, if Greenfoot is forked, the Greenfoot team can simply refuse to support the modified versions. When I sent this reply to a Greenfoot developer, it was met (like Bill’s experience with Scratch) with silence. Silence isn’t necessarily a bad thing; it may mean they’re contemplating alternatives.
Scratch and Greenfoot are potentially valuable learning tools. Maybe the developers are now considering maximizing that potential through licensing that encourages tinkering, widespread distribution and protection for official versions. Here’s hoping.