Probably a silly question re: GNU General Public License (GPL)

I can't recall ever using GPL licensed software in a for-money commercial endeavor. For some reason I assumed it wasn't allowed.

I just found something that is licensed under GPL and I want to make a website using it as the foundation and then charge users of the website a fee for the "service".

I know that I need to make my new work freely available under GPL and have no issues with that but I've read and re-read the GPL and I don't see anything restricting commercial use of the software.

Just looking for someone to confirm my understanding ... I can do this and still be abiding by the license right?

 

From my understanding of GPL, derived works made must be freely distributed in source code format. You can charge for the compiled version. You can also charge for services such as setting up and support.

This is my personal understanding of the GPL license.
You can read further here: http://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLAllowMoney

 

This page is well written with GPL FAQ.

hth

EDIT: Obenix is faster.

 

Thanks obenix. I think I'm clear and comfortable with the fact I have to make my new version GPL also.

My question is can I take GPL software and use it in a commercial manner.

For example, let's say there is GPL software for a job board. Can I take that software and mod it so website users have to pay to enter a job listing? I know I'll have to make my mod available to other webmasters that want the same mod, but I can I make the software a fee for service and make money from it? Nothing I see in the GPL states I can't, so I think I can.

 

Personal opinion: Yes, you can. The fees you charge is for the service to post a job listing and not for the software.

 

You can take GPL software, make modifications for your own use (i.e. create a payed job board) and not make the changes available to the general public.

You must make the changes available via the GPL if you are distributing your modified version at all - i.e. selling copies of your web site.

If you are making a modification to GPL'ed software, you are not necessarily required to make that mod GPL. You can distribute the GPL'ed software as you received it, then charge for your modification - either to do it yourself or via an install script or something like that.

The GPL becomes "viral" in the situation where you are distributing a modified version of the original software. As long as you distribute the base set of software as you received it - including copyright, license, etc., you are not bound to any licensing scheme for your "add-on".

If your modification cannot be distributed as an "add-on" or a separate install of some sort and you must distribute modified code or binaries, you must GPL your changes.

For example lets talk about PostNuke (assuming it's GPL'ed, which I don't remember whether it is or not):

1) You can make a post nuke add-on, such as an address book, and charge a fee for people to use your address book, and distribute it encoded with say zend to protect your code from ever being read.
2) You can create a post nuke web site, make a custom job board for it, charge people to post job listings, and never release any code to the public.
3) You can package your custom job board as a postnuke add-on, assuming it doesn't require changes to the freely distributed files, and charge for it, and never release any code to the public.

If however what you want to do is - Create a postnuke job board site, and distribute it as a single install - rather than have the end user install post nuke, then install your add-on - then you are bound by the GPL to release your code and all your changes under the GPL.

If the above did nothing but confuse you, I do agree with what obenix posted above - I'm just posting a slightly different angle on things that I think may be appropriate for your situation.

Somebody correct me if I'm wrong, but I'm pretty sure this is the way it works.

As another example - there are a lot of not-for-free not-GPL'ed apache modules available.

And another one - Urchin itself is packaged with Apache. The urchin code is not GPL, but apache is distributed as an accompanying piece of the puzzle. It automatically installs apache as part of the install, with all the correct configuration parameters necessary to alleviate the problem of one of their customers having to compile and install apache correctly without interfering with their existing apache install.

Again, Apache and PostNuke are open source projects, but I really don't know off hand if they are licensed under the GPL or a BSD-style license or some other license. I'm just coming up with examples off the top of my head that might better get my point accross.

 

Thanks for the detailed response.

<EDITED>Removed some stuff because after reading more I think you're probably 100% correct </EDITED>