A very small Linux operating system, known as Puppy Linux, has had a “major upgrade” after version 3.0 hit the streets this week.

What makes Puppy Linux different from other distributions of Linux is that the Puppy 3.0 Live CD can be run direct from the CD, without installing to a hard disk. Indeed, the operating system is just 97.6MB in size.

Puppy is designed to be a very small Linux operating system designed to be "reliable, easy to use and fully featured." The entire operating system and all the applications can be run entirely from RAM. It comes with applications such as SeaMonkey/Mozilla Application Suite, AbiWord, Sodipodi, Gnumeric, and Gxine/xine.

One of its most compelling features is that users can boot from the disk, work, and then save their files back to CD for the next time they boot the CD. It can also be run from USB storage sticks or Zip disks. This allows the Puppy operating system to be used on older computers, or as an emergency rescue system, a Linux demonstration system, or as a complete general purpose operating system.

According to developer Barry Kauler, Puppy Linux 3.0 is a major upgrade over previous releases. One of the major changes in this release is a move to make Puppy Linux and Slackware compatible to allow users to install Slackware packages on Puppy. Slackware is one of the oldest Linux distributions, and aims to be the most Unix-like Linux distribution.

“To that end, I used all the building block packages from Slackware 12, such as glibc 2.5, gcc 4.1.2 and gtk 2.10.13,” said developer Kauler. “Most of the libraries in Puppy are now from Slackware. Note, though, this does not in any way make Puppy a clone of Slackware - apart from aiming for binary compatibility, Puppy is fundamentally unique from the foundations upward.”

Kauler has also "totally rewritten the key scripts that control how Puppy boots up, is configured, and shuts down." Other changes include better USB writing method, after “finally getting periodic flushing of RAM to Flash drive working properly - this is part of a mechanism that constrains writes to Flash drives so that they don’t burn out.”