Opensource ad server company Openads has secured $5 million in venture capital funding, reports TechCrunch.

The firm operates an open source ad delivery server whose software is free to use under a GPL license. The company earns revenue by selling services that build on the core product.

Openads services 25,000 publishers, with ads running on 100,000 different sites. These includes FM Publishing's sites and about 30 additional ad networks which use Openads as a foundation.