When going through the process of opening Socialtext, we need to choose a license that is a fit for a commercial open source company. Commercial open source strikes the balance between freedom and profit motive, and the license you choose becomes a contract not just for the company, but a community.
The decision to open is easier for vendors than it was just a few years ago because of the common practice of Mozilla Public License-based licenses by companies such as SugarCRM, Zimbra, Alfresco, Scalix and about 10 others. MPL is the most popular OSI license and it allows for extensions (MPL section 6.1 says "However, You may include an additional document offering the additional rights described in Section 3.5." Section 3.5 ensure that the modifications must apply equally to every developer or contributor.).
Good thing too, because in my humble opinion no other licenses are a fit for commercial open source web applications.
For Socialtext, we made three modifications:
- Attribution: We believe that attribution provides positive incentives for creativity and innovation, as witnessed by the success of Creative Commons attribution licenses. Trademark is attribution. We require the display of the project's mark within the UI, not just the code, with a link back to the community that contributes to it.
- Network Use: Delivering an application over HTTP should the same as compiling, burning and distributing on a CD. If you distribute over the network, you should share your contributions with the community. See this wiki page for more details.
- Trademark Use: Section 6.3 says that if you make a modification to the license, you cannot use Mozilla trademarks within the license. So we called it Socialtext Public License, but we can reference MPL publicly or in the license expressly to point out the first two differences between SPL and MPL.
We put SPL out into the world after a lot of research and conversation, but decided to be open to granting more liberal rights in the future if demanded by the community. More importantly, while SPL is consistent with the Open Source Definition, we firmly believe in the mission of the Open Source Initiative and desire to submit to their process for sake of license proliferation.
While it is inside baseball for some, David Berlind has a very well researched post that asks, are companies using MPL extensions are abusing the term Open Source? I've spoken with David about this several times. I think his article provides a balanced view of those who believe the licenses are OSI compliant and those who do not. I'd also like to highlight OSI board member Danese Cooper's blog post on attribution.
But unfortunately I haven't had a chance to talk with David in a little while, as I would have highlighted that Socialtext submitted a memo to the OSI board for consideration on November 14th -- proposing a Generic Attribution Provision. I've shared the attribution memo on a wiki page, where you can find additional background information on the issue and the proposal to resolve it through a standard attribution clause that OSI could certify for any OSI license. This structure would be similar to how Creative Commons enables attribution as an option.