ResearchGate, a Germany-based social network for the estimated seven to eight million scientists around the world, has raised $35m in its series C round.
Bill Gates, a co-founder of software provider Microsoft, led the C round and was joined by venture capital firm Tenaya Capital.
Physicians Ijad Madisch and Sören Hofmayer and computer specialist Horst Fickenscher founded ResearchGate in 2008 to remove the arcane barriers to scientific collaboration and sharing.