Puppy Linux is a distribution of Linux intended to run entirely from RAM, and as such focuses on a small memory footprint. As of the writing of this text (February 2017), Puppy Linux 6 "Tahrpup" is the latest version, built upon Ubuntu 14.04 packages.

A benefit of running entirely in RAM is that slow optical media and hard drives do not need to be involved. It is possible, however, to install Puppy to a hard drive. For RAMdisk functionality, Puppy requires 128 MB of RAM; systems with less RAM will require that parts of the OS be installed to a hard drive, or left on the CD.

The Puppy Linux desktop, which consists of the JWM window manager and the ROX desktop environment.

For being a compact Linux distro fitting within 128 MB of RAM, Puppy includes a rather generous selection of software. Anything the average user could want to run is installed by default, although the packages chosen are obviously lightweight versions.

Things that are not bundled can be easily added on afterwards.

The Puppy Linux installer.

It took a few tries to get the installer to actually work. At first, it was spitting out cryptic error messages about disk geometry that made no sense to me. I later found out that this was because I had accidentally tried to re-use a corrupted VDI file with VirtualBox. However, I still had difficulty with partitioning issues until I set VB up to emulate an IDE controller instead of a SATA one.

The Puppy Linux file manager. It has got two views, a list view and a details view. Folders open up within the same window.

Unlike a lot of Linux distros, Puppy recognizes and can make use of my USB flash drives without any unnecessary use of profanity or hair-pulling!

Puppy includes an [un]mount tool for media, on the off chance that it fails to do so automatically. Presumably this is most useful for floppy diskettes, which still do not auto-mount and auto-unmount in Linux yet for some absurd reason. However, this kind of tool can be dangerous in the face of an unskilled user. Fortunately, it seems to be impossible to accidentally unmount the system or swap drives.