What is JeOS?
JeOS (just enough operating system) is a highly customized operating system built for a specific application. The acronym is pronounced "juice."
JeOS builds are popular with software vendors and developers who are creating test systems or virtual appliances. A virtual appliance is simply a virtual machine (VM) image file that has a preconfigured operating system (OS) and a single application. (The preconfigured OS is the JeOS.)
A JeOS only includes the bits of a full-blown operating system that are required to support the application and any other third-party components that are packaged in the appliance. Configuring the JeOS and the application together in a single package helps avoid installation issues and errors.
Learn More About IT:
Ubuntu JeOS is a lightweight version of the Ubuntu Server operating system.
Learn how to configure Ubuntu JeOS as a Secure Shell (SSH) server.
Wikipedia has an entry about JeOS.