Virtualisation specialist Citrix has announced it is officially joining the OpenStack Foundation as a corporate sponsor, the open source organisation it left four years ago in order to pursue the rival Cloud Stack initiative.

Citrix said it had contributed to the OpenStack community fairly early on, but wanted to re-join the community in order to more formally demonstrate its commitment towards cloud interoperability and standards development.

As part of the announcement the company also said it has integrated the NetScaler and XenServer with OpenStack.

“We’re pleased to formally sponsor the OpenStack Foundation to help drive cloud interoperability standards. Citrix products like NetScaler, through the recently announced NetScaler Control Center, and XenServer, are already integrated with OpenStack,” said said Klaus Oestermann, senior vice president and general manager, delivery networks at Citrix.

“Our move to support the OpenStack community reflects the great customer and partner demand for Citrix to bring the value of our cloud and networking infrastructure products to customers running OpenStack,” Oestermann added.

Citrix is one of the biggest backers of CloudStack, an Apache open source project that rivals OpenStack. Citrix was aligned with OpenStack at the outset but in 2012 ended its commitment to that project in order to pursue CloudStack development.

That said, the move would suggest Citrix is aware it can’t continue going against the grain too long when it comes to vendor and customer mind-share. OpenStack, despite all of its own internal politics and technological gaps, seems to have far more developers involved than CloudStack. It also has more buy-in from vendors.

All of this is to say, going the CloudStack route exclusively is counterintuitive, especially in cloud – which is all about heterogeneity (which means interoperability is, or should be, among the top priorities of vendors involved). But, Citrix maintains that it will continue to invest in CloudStack development.

Laurent Lachal, lead analyst in Ovum’s software practice told BCN the move is a classic case of “if you can’t beat ‘em, join ‘em.”

“But there needs to be more clarity around how OpenStack fits with CloudStack,” he explained. “The CloudStack initiative is no longer as dependent on Citrix as it used to be, which is a good thing. But the project still needs to get its act together.”