[dashr]

I'm the CTO at TUMIS.com, we are one of 2-3 boutique dev shops in the Bay Area, CA, US that work 99% with social justice organization, social enterprises, green businesses, campaigns across the country. We are not a non-profit- more like a B corp with worker shareholders. Have been in business for 10 years. There are similar shops that meet regularly via NTEN and TechSoup conferences. Taproot Foundation just received a very large gift - they do most of what you described, they have some paid staff to wrangle the volunteers.