DeLi Linux stands for "Desktop Light" Linux. It is a Linux Distribution for old computers, from 486 to Pentium III or so. It's focused on desktop usage. It includes email clients, graphical web browser, an office programs with word processor and spreadsheet, and so on. A full install, including XOrg and development tools, needs not more than 750 MB of harddisk space.
The trick is, that DeLi Linux uses only "lightweight" alternative software. If you are looking for the newest KDE, GNOME or Mozilla, DeLi Linux will not make you happy. The test computer is a PII laptop with 64 MB RAM, and all apps which comes with DeLi Linux are running smoothly.
Deli was replaced by ConnochaetOS Linux. It's produced by the same developers. It's targeting computer systems with a little more horsepower (minimum recommended i586, 64MB RAM, 2 GB hard disk), but still mainly designed for older systems. It uses package tools from Arch Linux and eglibc instead of glibc. It concentrates on Free Software (Free as in the Free Software Foundation/GNU standards of the definition).
http://www.delilinux.de/ (Working as of 26 Mar 2009)
Old Links (Not working):