Debris Linux:
"The goals for the distro include keeping it small, compact, and keeping hardware requirements as modest as possible to allow Debris to run well on older hardware. Recommended system requirements are a Pentium II or better processor, 128 MB RAM, and 2 GB of hard disk space. A fully installed system takes up just 850 MB of disk space, making Debris ideal for low-end or first-generation netbooks and nettops with 2 or 4 GB of SSD storage as well as legacy systems with storage limitations. In many ways Debris Linux is to Ubuntu what distributions like Slax and Wolvix Cub are to Slackware. A relatively small but active community has grown around the distro and there is an active user forum."
http://distrowatch.com/table.php?distribution=debr is