8. References to Non-Free Software and Documentation

A GNU program should not recommend use of any non-free program. We can't stop some people from writing proprietary programs, or stop other people from using them. But we can and should avoid helping to advertise them to new customers.

Sometimes it is important to mention how to build your package on top of some non-free operating system or other non-free base package. In such cases, please mention the name of the non-free package or system in the briefest possible way. Don't include any references for where to find more information about the proprietary program. The goal should be that people already using the proprietary program will get the advice they need about how to use your free program, while people who don't already use the proprietary program will not see anything to encourage them to take an interest in it.

Likewise, a GNU package should not refer the user to any non-free documentation for free software. The need for free documentation to go with free software is now a major focus of the GNU project; to show that we are serious about the need for free documentation, we must not undermine our position by recommending use of documentation that isn't free.