Is there any way to use GPL software without having to distribute my proprietary source code?
In some cases, yes. The GPL states that if GPL code is “merely aggregated” with a proprietary program, then the proprietary program will not be considered a derivative work of the GPL code, and thus will not itself be under the GPL. Also, some GPL elements, such as files in the Gnu C++ library, come with a “runtime exception” that can exclude proprietary code that is run with the GPL code. The Lesser General Public License, designed principally for use with certain libraries, is a slightly less restrictive version of the GPL. It may not require the licensee to make its proprietary source code. None of these potential exceptions has been judicially tested in the U.S. and their uncertain nature is cause for concern among proprietary software developers and investors.
