Usage of mix licensies in commercial use [duplicate]

Question

This question already has answers here:

Can I use GPL, LGPL, MPL licensed packages with my application and make it closed source? (5 answers)

Closed 5 years ago.

I'm developing a CMS, inside it I use many various plugins/addons wich licenses mostly like MIT, GNU, GPL (such as jQuery, nivoSlider, DataTables and so on..). After reading those licenses I believe I can use them inside my CMS and charge users for my CMS.

In my project I have a specific folder where I store all these plugins with their license and all notices. Is this the correct way? Or should I somewhere on my site notice the all plugins Im using with the path where they can be found in my project folder?

What about if I would use my CMS as SaaS? The end users would not have the access to source files so I would not exactly be distributing it. Is it posible?

And lastly, can I protect my own source files with the license? Wouldnt it collide with the other ones? I would like to protect it as much as I can at least in a legal way as I cannot really protect it as all PHP files are easy accessible.

Thank you for any help. Also note that I have read a lot about license, but these are things I would like to confirm or to see if I misunderstood something.

Answer 1

The MIT and BSD licenses allow you to use them as a library and still keep your work under any license you want. The GPL, on the other hand, doesn't allow this. When you use a GPL library, the whole project must be GPL. There is a special version of the GPL, the LGPL (Library GPL or Lesser GPL) which specifically allows to use the library in non-GPL projects.

But the GPL only applies to distribution of software. When you provide the software as a service, you don't distribute the software. That means you do not need to provide the sorcecode to anyone. There is a special version of the GPL, the AGPL (Affero GPL) which closes this loophole and requires you to license the software to anyone who uses it via network.