Bruno's work is given for free, and if you don't share your changes back, keep it secret behind the server, it doesn't help the Movuca project. So for Bruno the GPL or even AGPL is a good option, as it keeps the code free (as in freedom).
CMS is very different to a framework like web2py, which is only a base for application development and could be seen as similar to a system library. CMS is an application itself. It's not a component used to build bigger projects. The FSF discourage use of LGPL in such cases, because they goal is to spread and increase adoption of the free software. So they favor a scenario in which your software is released under the GPL, as all work derived from it would have to become free software too (which is not the case for LGPL). Also, I don't see any contradiction between GPL or AGPL and "commercial intentions". Your client is paying for a customised solution and is getting one no matter if the license is LGPL, GPL or AGPL. The only difference here is for Bruno and the community of people working with him on the CMS. They might ask for the source code and benefit from changes made by others. The same way as those others benefited in the first place from Bruno's CMS as they didn't have to write it from scratch. It's a win win situation. Where do you guys see problems with adoption and commercial use? GPL will prevent anyone from making a proprietary system that includes your code (LGPL allows that). However, it would be still possible to do it without code distribution, for example in a software as service model. Only AGPL will prevent that, as it requires to make the source available whenever the code is deployed on a server.
