Zenoss, which develops management software for unified physical, virtual and cloud-based IT infrastructures, has closed a $25 million C funding round led by growth equity investor Summit Partners.

That makes $45 million altogether although Zenoss has reportedly been at cash flow breakeven since last year with most of the revenues coming from the US.

Existing investors Grotech Ventures, Intersouth Partners and Boulder Ventures also participated in the C round, which will be used for product development and global expansion.

The company wants to push into Europe and the Pac Rim by the end of the year.

Tom Jennings, a managing director of Summit Partners, will join the Zenoss board.

Founded in 2005, Zenoss offers a next-generation IT operations platform that includes unified monitoring, scale event management, real-time service impact, root cause analysis and automated remediation.

The widgetry is purpose-built for managing virtual and cloud based infrastructures on top of legacy environments.

It's built on an open software architecture around a real-time service model and lets IT organizations consolidate their operational tools and automate their core processes.

The result is said to be improved service quality, significant cost savings and more rapid response to change.

Zenoss also wants to expand its open source community which has downloaded 2.4 million copies of its open source product, most of them going to users outside the US.