VMware has acquired intellectual property and some employees from software-defined networking (SDN) startup PLUMgrid, SDxCentral has learned.

The deal closed Friday, a VMware spokesman confirmed. VMware isn't disclosing further details, and there's no word yet on which executives of Santa Clara, California-based PLUMgrid might be joining VMware.

PLUMgrid Marketing Manager Waqas Khalil announced the moves in a blog posting on Friday but didn't name the buyer. His post also reads as a goodbye message to PLUMgrid's customers and supporters.

PLUMgrid's people are an obvious fit for VMware, as the company boasts experts in network virtualization, security, and OpenStack. VMware has been covering the first two categories with NSX, and it's been offering its own OpenStack distribution as well.

On the surface, PLUMgrid's technology, formally introduced in 2013, might appear to cover the same ground as NSX. But PLUMgrid, while part of the early phase of startups attempting to capitalize on SDN, took a different approach from contemporaries such as Nicira (acquired by VMware) or Big Switch Networks.

Rather than create an SDN controller to dictate instructions to switches, PLUMgrid created IO Visor, an I/O processor that sits in the Linux kernel and controls virtual domains for network virtualization, monitoring, and security. IO Visor has since become a Linux Foundation project.

SDN and network virtualization were a playground for startups circa 2011, but the market was quickly overtaken by big-company products such as Cisco’s Application-Centric Infrastructure (ACI) and VMware's NSX (which, of course, began its life at startup Nicira).

PLUMgrid tried to broaden its prospects by offering its software as an OpenStack companion. The company also brought in Cisco veteran Larry Lang as its CEO in June 2015.

The startup did manage to score some noteworthy customers. Swisscom was an investor in the company, and its IT services unit was an early customer. It also announced NTT SmartConnect, a streaming video service based on an OpenStack cloud, as a customer in 2015.

Founded in 2011, PLUMgrid raised $27 million in funding, including a $16.2 million Series B in 2014.