Internetworkers: http://www.ibiblio.org/internetworkers/

[Geoff Davis <geoff AT geoffdavis.net>]

Thanks to those who replied.  I guess I didn't make myself clear: the  
non-profit in question is looking for recommendations for service  
providers, not for CMSes.  They aren't going to maintain things in- 
house.  They'd prefer a company to an independent contractor (less  
risk of the run-over-by-a-bus problem).

Their site is sufficiently modest that I don't think the technology  
stack matters so much (as long as it doesn't totally suck).  What  
they're looking for is a company that can take care of training /  
support / etc now and down the road.

Any suggestions?

Geoff