I wrote an article entitled Free Software for Fun and Non-Profit for the CharityChannel E-Philanthropy & Technology Review newsletter:
Using free software means that nonprofit organizations can dedicate their precious resources in much more effective ways. Instead of paying for the right to use a piece of software, organizations can improve their staff skills by training them how to use their free software. Instead of spending time keeping track of their license compliance in the dreadful event of a software audit, organizations can spend time actually using -- or improving -- their free software. And instead of diverting their capital to a corporate headquarters in a different state, organizations can focus on growing local talent and giving back to their own communities.
Go read it!