Based on this wikipedia paragraph, what original tool was Kubernetes based on?

Context: Kubernetes was announced by Google in mid-2014. The project was created by Joe Beda, Brendan Burns, and Craig McLuckie, who were soon joined by other Google engineers, including Brian Grant and Tim Hockin.

The design and development of Kubernetes was influenced by Google's Borg cluster manager. Many of its top contributors had previously worked on Borg; they codenamed Kubernetes "Project 7" after the Star Trek ex-Borg character Seven of Nine and gave its logo a seven-spoked wheel. Unlike Borg, which was written in C++, Kubernetes source code is in the Go language.

Kubernetes 1.0 was released on July 21, 2015. Google worked with the Linux Foundation to form the Cloud Native Computing Foundation and offered Kubernetes as a seed technology. In February 2016, the Helm package manager for Kubernetes was released.

Answer: Kubernetes was originally based on Google's Borg cluster manager tool.