Better put on your hunter orange, because it's open season for OpenStack.

Cisco, IBM, and Oracle are all scooping up OpenStack talent and technology through acquisitions, with a slew of tie-up news out this morning. If you were looking for a clear sign that OpenStack has the attention of the big vendors, this might be it.

Cisco's latest acquisition target is Piston Cloud Computing, the 4-year-old OpenStack orchestration firm based in San Francisco. The acquisition would be the second OpenStack startup Cisco has bought in less than a year, following the September purchase of Metacloud. Terms of the Piston deal were undisclosed.

The Piston team would bolster Cisco's efforts around Intercloud, the company's private cloud interconnect strategy, Cisco's Hilton Romanski writes in a company blog post announcing the deal.

Meanwhile, IBM has scooped up OpenStack-powered private cloud provider Blue Box. Terms were undisclosed.

In addition to augmenting IBM's OpenStack arsenal, Blue Box gives IBM a private-cloud offering to add to its managed cloud services.

Not to be left out, Oracle has snapped up the intellectual property of failed OpenStack startup Nebula, Fortune reported this morning. That land grab follows the earlier disclosure that Oracle had hired 40 former Nebula engineers. Nebula shut down in April.