There are a number of small Linuxes out there, but when they called this one Damn Small, they really meant it! It fits onto a 50MB business card CD yet boots to a graphical desktop. No, it doesn't have all the latest whizzy features, but what it does, it does very well - and extremely quickly. Damn Small Linux, DSL from now on, is light enough to run on a 486 processor with only 16MB of RAM (although increasing this to a massive 32 MB does speed things up).
DSL is a live CD distro that can run a from a business card sized CD, a USB flash drive or be installed to your hard drive. You can even run it within Windows. As well as a desktop, complete with three (!) web browsers, email, office software and even a few games, DSL also includes FTP, Web and file servers and is very popular as a way of turning an old, redundant PC into a server for a home or small company network.
If you have more than 50MB to spare, and most of us do these days, DSL can be expanded with a number of "MyDSL" extensions to add extra features and software you may need. There are plenty of MyDSL modules to download and the tools to create your own if you need some specific software.
An amazing amount of software in such a small package