As an aside, things to be very careful about with bridges is the licensing with other Open Source projects. I think that pretty much anything that interacts with some of the projects mentioned in this are required to be licensed under the GPL. We take a
different approach at MODx, because frankly we don't view interaction with a public API as something that should "infect" another project with a viral GPL license. I guess we're a bit of an anomoly in the traditional Open Source world because we really are very pro-business when it comes to licensing (see
http://www.thrash.me/tech-and-modx/open-source-vs-open-core.html).
At the risk of taking this thread horribly off-topic, if you wanted a business-friendly license, you should not have chosen GPL.
The practicality of law is, it's not what is legal or illegal, but what can and will be prosecuted. If the GPL is the law, then the Free Software Foundation is the enforcer, and the FSF has been doing a lot of saber-rattling and reinterpreting of the GPL lately. In the last few years, they've gobbled up virtual real estate by claiming that not only plugins and bridges, but also styles and CSS files fall under GPL viral license. They've turned third-party commercial development for Wordpress, MediaWiki, Joomla, etc. into a potential legal minefield.
When Joomla announced that they were adopting the FSF's most stringent, anti-business interpretation of GPL, they scared the hell out of the business and third-party add-on communities. It didn't help that you had a few nutjobs speaking on behalf of Joomla who think open source software is right up there as a
cause célèbre with world peace and global warming. There were hundreds of angry threads on the Joomla forums for almost a year from professional developers who had built a business on developing for Joomla. As a result, dozens of serious third-party developers departed Joomla. It almost killed the project. I think Joomla realized how much damage they did because they haven't broached the subject of licensing since.
GPL has the potential to tie the hands of your customers, and limit the options of third-party integrators. If I want someone telling me what software I can and cannot do with my software, and how I may or may not integrate it, I can just get that from Microsoft or Apple, and usually get a more mature product with better tech support.
There were so many licenses to choose from.
If you wanted to demonstrate you are pro-business, you really ought not have picked GPL.
I can pass a law saying "Red cars are illegal" and then say I won't enforce it, how many businesses will take the fiscally unnecessary risk of ordering a fleet of cars painted red?