Stephen Downes

Frontiers began as a "researcher-led initiative envisaged as being 'by scientists, for scientists' the mission of Frontiers was to create a 'community-oriented open access scholarly publisher and social networking platform for researchers.'" After flirting with various business models (even including a business methods patent) it seems to have settled on a sustainable, if sketchy, existence based on publication fees. This article is a fascinating overview, and as a bonus there's a link to a full interview with Frontiers CEO and co-founder Kamila Markram (pictured) at the end.