open source licenses are confusing

I recently attended the Technical SIG 'Open-Source in GIS' Event and it was actually fairly interesting because it was basically talking about Open Source in GIS (Graphical Information Systems) and lets face it, you get a free lunch.


There was a really good talk Introduction to Open Source in GIS and you can read the slides here if you are interested.

This particular talk talked about the different open source licenses, which is something I have a very hazy knowledge of and to be honest I'm still am not totally sure what the hell is what. It's one of the questions you come across as a programmer, the main question being

"am I allowed to put this in with my source code without being taken to court"

I feel I should add at this point that anything written below is not a legal definition, so go and read the links if you want make sure you aren't breaking the law.

There are a few slighty different licenses which mean different things. There are two types of free, which is nice and confusing.

Free as in free speech

and

Free as in free beer

I have tried to find some information on this and Wikipedia does a half decent job although there are lots of similar sounding topics. This quote from wikipedia licenses

"In computing, software that is copyrighted and licensed under a software license is done so principally under two categories of licensing schemes. There are open source / free software schemes, and there are closed source / proprietary schemes. Within these schemes are further classifications."

Alot of differences between the licenses involves the distribution of the source code. The first license definition I decided to check out was the GNU because I use software with this license so why not check it out, there website license explanation is here license list

These quote from the GNU project explains the free license- open source license

"We classify a license according to certain key questions:

• Whether it qualifies as a free software license.
• Whether it is a copyleft license.
• Whether it is compatible with the GNU GPL. (This means you can combine a module which was released under that license with a GPL-covered module to make one larger program.)
• Whether it causes any particular practical problems."

copyleft by the way is the opposite to copyright, basically saying is it free (not copyright) and you allow anyone . The free software movement seem to kicked off by Richard Stallman he even created the Free Software Foundation (FSF) after he had created the GNU project

aha at last, this page has a definition of free software I'm understanding the free speech and not free beer thing now. Free software from what I understand means that you don't want any money for it but there are different flavours with regards to what people can do with it.

on the GNU website definitions, the clear fans favourite

"GNU General Public License, or GNU GPL for short.

This is a free software license, and a copyleft license. We recommend it for most software packages."

I believe this license is the lest prohibitive and thus my favourite.

This blog entry is getting completely lost and I haven't got a clue but I have got another link to a decent article which clearly explains open source licensing so why should I bother, this is pretty helpful, open source licensing

by the way none of what I have wrote is worth the paper it's written on in a court of law because it's obviously the ramblings of a madman.

I hope the links supplied have helped you understand and if you have write some comments so that I can.