Does anyone know a commonly used closed source license that allows non-commercial use of a library? I would like to provide a free (as in beer) version of the library but I don't want to release source code and I don't want people to make money with it without my permission.
The reason for not giving away the source code is because I don't want the library to start leading it's own life outside my control. If you have any good suggestions to avoid that, I'm interested as well.
Check out BSD licences and see if these suite you. I personally like this, because it doesn't obligate me to release source code. Of course, if you own the copyright to the original you have even more free range. Also, many licenses can be described as "BSD-like", that is, they look like the BSD license, but have extra- or change some clauses.
Checking out the related link How to write a basic closed-source license for a software project?, Charlie Martin has a great suggestion, and it's the law. Legal advice can only be given by a licensed attorney ;-)
Update: On thinking of your desire for "people not to make money off of it", you may want to bookmark and look at the Creative Commons license builder. It seems like you can specify what you want out of it, and it fills in a template. I've come across a lot of projects, personally, that use some form of Creative Commons license, and they've undergone several revisions over the last several years. Check it out, see if it suits you. I'm guessing that you'll check "Non-commercial" and either "No-derivative" or "Share-alike".
If you own the library, simply release it under any terms you want.
You don't have to release the source code, normally a header and a .lib/.a or .so/.dll would be enough.
The Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 license sounds like what you want.