Not a lawyer. In the US, the copyright related to contractor work is called "work for hire". See http://en.wikipedia.org/wiki/Work_for_hire#Law_in_the_United_St

Not a lawyer. In the US, the copyright related to contractor work is called "work for hire". See http://en.wikipedia.org/wiki/Work_for_hire#Law_in_the_United_States http://en.wikipedia.org/wiki/Work_for_hire#Law_in_the_United... . If there was no specific written statement that you were doing work for hire, then you control the copyright. I know even less of Canadian law, but http://smart-biggar-web-com.sitepreview.ca/en/newsletters/Intellectual_Property_Magazine_Dec2010.pdf http://smart-biggar-web-com.sitepreview.ca/en/newsletters/In... says "In Canadian copyright law, an assignment of copyright must be in writing to be valid." So it appears that you have the copyright to the code you wrote. The next question is, should you publish it without informing your former client, or potentially giving veto. That's sounds like it's a sensitive topic that will depend on your client, the amount of code you want to publish, how much noise they can raise should they get angry, etc. Personally, I would ask them, describe what I want to do, and be willing to not publish should it be a problem, or to only highlight/describe the parts of interest without including the full, working sources you got from them - even if that were allowed under the licensing terms and copyright law. But I'm in a small field, and I've produced a lot of packages so leaving out just one is not an issue. On a related topic, under GPLv3, distribution to contractors is not considered a distribution that triggers GPL protection: > You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you. You might use that as an idea of the spirit behind how to use GPLv2.