Mirantis, which describes itself as the leading "pure-play" OpenStack cloud computing company, today received its strongest affirmation yet with the announcement of $100 million in series B funding, which makes Mirantis the recipient of the largest investment of its kind in open source history.

Mirantis says the funding will allow it to double the size of its engineering resources for developing its OpenStack distribution, Mirantis OpenStack, which it promotes as the best vendor-neutral, lock-in free OpenStack platform. The financing will also support further investment in the company's other OpenStack products and services, including its rivate cloud-as-a-service platform, Mirantis OpenStack Express.

The company promises that the investment will benefit general development of the OpenStack code base, too, to which Mirantis is currently the third most important contributor. In a statement, Mirantis said its work on OpenStack will include "particular focus on enterprise-grade reliability and ease of use."

The funding is led by Insight Venture Partners, with additional support from August Capital, as well as previous Mirantis investors Intel Capital, WestSummit Capital, Ericsson, and SAP. Insight Venture Partners' Alex Crisses will join the Mirantis board.

Mirantis's backers have expressed confidence in the company's ability to become the predominant OpenStack vendor in a crowded cloud computing ecosystem. "Mirantis is already leading the OpenStack ecosystem," said Vivek Mehra, general partner at August Capital. "We are committed to helping it become the principal cloud vendor."

Crisses added, "Mirantis delivers on OpenStack's promise of cloud computing at a fraction of the time and cost of traditional IT vendors, and without the compromise of vendor lock-in. Their customer traction has been phenomenal."