Puppy Linux

A tiny distribution (historically well under 300MB) designed to run entirely in RAM after booting, so it stays fast even on very old hardware and can boot from almost any removable media.

Lightweight & Old Hardwarelightweightold-hardwareruns-from-RAMlive-USBDownload ↗Official site ↗Docs / Wiki ↗

Based on

Independent (multiple variants, some Ubuntu/Debian-based)

First released

2003

Package manager

PET/PPM (Puppy's own package format)

Desktop environments

JWM, Openbox

Puppy Linux's defining trick is loading its entire filesystem into RAM at boot, so once it's running, disk speed stops mattering at all -- an old spinning hard drive or a slow USB stick performs the same as a fast SSD, because the system barely touches storage after startup. It's less a single distribution than a build framework: several 'Puppy' variants exist built on different upstream bases (Ubuntu 'woof-CE' builds, for instance), sharing the same lightweight philosophy and tools but differing in package compatibility. Its small size and RAM-resident design make it a favorite for rescue disks, ultra-old netbooks, and anyone who wants a genuinely instant-feeling boot.

MirrorNest doesn't mirror distro ISOs — installation media should always come straight from the project's own official download page (linked above), so you get the correct checksum/signature to verify against.