The University probably gets the copyright to your code.<p>There are several ways around that. One is to link to a GPL'd project. Now they own the copyright, but they have to keep the source code available for others to use for any purpose. Including your business. (If in doubt, you can always do something like cut-n-paste Emacs' malloc, link in libreadline, etc.)<p>Another option is to just rewrite the code. Copyright only covers verbatim redistribution of the literal program text, which is generally not too valuable. It is very easy to write a program a second time. Ideas and algorithms are not copyright-able, after all, nor is the experience in developing software you gained from writing it the first time. Those things are where the value is, and copyright does not protect them. (Software patents may, but the University will have to apply for one before that's even an issue. Then they will have to spend their own money to sue you, and then they will have to collect damages. Not going to happen unless you become the next Google, and if you do, you can afford to pay them off.<p>OTOH, software patents are almost dead. So this might not be worth worrying about.)<p>So anyway, to be extra safe, be open source, or just redo anything that you did with University resources. That is a lot faster than dealing with legal problems that may arise if you are successful.<p>(Then again, most startups fail pretty quickly, so perhaps it's not really worth your time to "care" this time around.)