TechSoup connects nonprofits, foundations, and libraries with tech products, services, and learning resources.
http://www.techsoupforlibraries.org/
From the site:
TechSoup has the products you need to maximize your technology services to your community. Whether you’re looking to upgrade your public access computers, seeking new software, or looking for a way to keep your technology secure, TechSoup’s library technology donations can help you make it happen.
Join TechSoup and check your eligibility to get a complete list of donation programs your organization is likely eligible for, including Microsoft, Adobe, and Symantec products.