Mixing Software Licenses

[eluser]Cro_Crx[/eluser]
Hey all

In my spare time I've been writing a CMS based on CodeIgniter so that I can use it in my freelance projects to save myself time (as I seem to be falling into the trap of developing the same sort of system over and over again).

I've been using DMZ (Data Mapper Overzealous) because ORM is just awesome and I was looking into using either using the google anlaytics API or Piwik API/Library to allow the CMS to track user visits.

Lets' just assume i'm going to use Piwik (I haven't decided yet though). So I've had a look and CI uses it's own license which is fine, DMZ uses the MIT license and Piwik uses the GPL open source license.

So I understand all 3 licenses (at least i think i do) in terms of what you can/can't do with each, although i'm not fully sure how i'm able to distrubute the software.

Primarily it will be me creating websites for clients using the CMS and installing everything for them, but what do I do for the licenses, do I copy all 3 licenses to the server ? Is that allowed ?

In the future when it's complete I was planning on distributing the software as open source. The GPL license says that if you use their API/code then you need to make your software GPL licensed as well.

Anyone know a bit about this and can help me out ? I've already searched the forums and couldn't find anything about multi software licenses

[eluser]Jan_1[/eluser]
Interesting.
On the first view
you have to follow the requirements of each licence.
Also make clear in your legal info what is been used, also how and where.
Maybe you put a link to the licences also there.

[eluser]Cro_Crx[/eluser]
Ok, i've done some more reading and found that you can release software under GPL if it has parts that are under GPL compatible licenses. MIT is GPL compatible. I can't find any references of CodeIgniters license being GPL compatible, although Bamboo Invoice seems to be licensed under GPL (so i'm assuming it should be). Maybe I should ask Mr Allard ?

So if CodeIgniters license is compatible then I could release the whole lot with a GPL license attached.