SliTaz is distributed for Raspberry Pi as a series of files with a size less than 100 MB uncompressed, providing a fast, robust and elegant system who work entirely in memory.
Another distribution to ARM devices.
SliTaz run in RAM when booted with an compressed root file system called an initramfs/initrd. The amazing is that the whole system will be loaded in just 20MB of available RAM.
The list with supported packages is still low, but their functionality to perform server potential is so great. It can even be generated with a proprietary tool and get a fresh raspberry flavor :P
You will need to uncompress the base package and create in your SD three partitions: boot, swap and root . Then run the installer and that's all.
I have not made ??it to work by a permissions problem, but I hope do it soon and offer to you a deeper analysis.
Link: List with some apps