"The basic idea is that the source code is publicly available for people to look at and modify and that it costs nothing to use as long as you’re building a GPL application with it and give out your source code too"
Can anyone confirm whether this is actually accurate? I'm not sure it is...
Not entirely. If you're building an application based on GPL licensed code, which is not handed over to the an other party, you're not required to handover any adjustments you've made in the GPL licensed code. That's what is referred to as the 'Services as a loophole' construct (ab)used in the GPL. See also this 2007 article by Tim O'Reilly: http://radar.oreilly.com/2007/07/the-gpl-and-software-as-a-s...
Btw, The AGPL tries to prevent this loophole and does require you to share adjustments made by you on AGPL licensed code even if your only using the software as a service and the other party will not receive the application/code.
I've been reading up on GPL because I know little about the nuances, but I think you only need to GPL and provide the source code if you distribute it to others. Web seems tricky for GPL, but I thought that was the purpose of AGPL. Please correct me it I am wrong.
You're correct that for a server side web project the GPL doesn't make you distribute source since you never distribute the binary. For client side javascript stuff though you ARE distributing the result (minified JS or whatever) so you do have to distribute the original source.
Can anyone confirm whether this is actually accurate? I'm not sure it is...