The Ismaning, Germany-based Linux software and server vendor was spun off from appliance and server vendor Pyramid Computer GmbH in August 2005, providing a new home for Pyramid’s open source technology.

Atlas Venture and Wellington Partners enabled the spin-off with an investment of 5m euros ($5.9m) and that has now been extended to $8.4m with the addition of Intel Capital, as Intel continues to invest in open source technologies.

Collax said it will use the funds to expand its presence in Europe and prepare to enter the US market in the third quarter of this year.

The company’s products include Collax Business Server, an all-in-one Linux server package targeted at SMEs, as well as Collax Open-Xchange Server, based on a joint development with Open-Xchange Inc. The company also sells a number of Collax Appliances pre-installed with the Collax Business Server software, offering scalability from 20 users to over 1,000.

Intel has invested in a number of open source infrastructure software companies, including JBoss Inc, SpikeSource Inc, Black Duck Software Inc, and Zend Technologies Inc.