Ubuntu JeOS

Ubuntu JeOS (pronounced "juice") is a discontinued variant of Ubuntu that is described as "an efficient variant ... configured specifically for virtual appliances." It is a concept for what an operating system should look like in the context of a virtual appliance. JeOS stands for "Just enough Operating System." JeOS has been replaced by Ubuntu Core, which is now an officially supported minimal variant of Ubuntu.

Its first release was Ubuntu JeOS 7.10, and since the release of Ubuntu 8.10 it has been included as an option as part of the standard Ubuntu Server Edition.

Supported platforms
The latest version of JeOS is optimized for virtualization technologies by VMware, Inc. and the Linux Kernel-based Virtual Machine.

Specifications
Specifications for version 8.10 and above include:
 * Part of the standard Ubuntu Server ISO image
 * Less than 380 MB installed footprint
 * Specialized server kernel
 * Intended for VMware ESX, VMware Server, libvirt and KVM
 * 128 MB minimum memory
 * No graphical environment preloaded