Mendix is a privately held company, founded in the Netherlands in 2006 by Derek Roos (Chief Executive Officer) and Derckjan Kruit (Vice President of Corporate Development), although it's HQ is now in Boston, Massachusetts. Its leadership team is listed here.
Major investors include Prime Ventures and HENQ Invest from the Netherlands ($13 million) in 2011; followed by Battery
Ventures and Prime Ventures ($25 million) in its Round B financing in 2014—see investor list here. The company is now growing well (it claims triple-digit growth since 2009) and is playing a leading part in the growing PaaS (Platform as a Service) development sector.
According to Mendix, "it was founded on the premise that if you make development radically faster and simpler while improving collaboration between IT and the business, you'll deliver better applications and drive significant business value". It is hard to argue with that, but what it actually means in practice is that Mendix is a model-driven, high-productivity, PaaS development environment competing with plafforms such as OutSystems Platform and Salesforce1.
Mendix now has some 450 active customers (most of its sales are in the USA and Europe) and a strong global partner program (with over 50 partners across North America, Europe, South Africa, the Middle East, and Asia). Customers include respected firms such as ABN AMRO, Dun & Bradstreet, GE and Yahoo!. Significant services partners include Accenture, Capgemini, and Sogeti.