Question

We’re evaluating a couple of Python libraries for Graph manipulation. We tried ‘networkx’ (http://networkx.lanl.gov/) and ‘igraph’ (http://igraph.sourceforge.net/).

While both are excellent modules, igraph is faster due to its nature – it’s a Python wrapper over libigraph – a blistering fast graph C library (uses LAPACK etc).

Now, the igraph library is GPL licensed. My question is: Can I import igraph and use it in my commercial Python script?

(This is a general question, not just limited to igraph. Apologies if the answer is obvious – I’m a license-newb!)

Thanks,
Raj

EDIT: More specifically, does simply importing a GPL Python module make my commercial code liable to be released to the public?

Answer 1

IANAL, but:

Now, the igraph library is GPL licensed. My question is: Can I import igraph and use it in my commercial Python script?

YES. You can write commercial software and distribute it under the GPL. Nothing on GPL prevents commerce. It even explicity says that you can SELL your software at will,

More specifically, does simply importing a GPL Python module make my commercial code liable to be released to the public?

NO. You don’t have to release anything. You don’t even have to distribute anything.

If you ever distribute your program to someone, you must give (to this person only) the source code, and give full freedom to modify and distribute it under the same license.

Distributing something under GPL or using GPL libraries in your code doesn’t force you to create a website and put your program for everybody in the world.