Void

[labbe5]

For the curious, Void is similar to Puppy. Puppy is not a run-of-the-mill distro, there is a steep learning curve to be at ease with it, but once you understand its ins and outs, it feels right to use it, because of its small footprint and low ram usage. If you use an old desktop or laptop, it is one of the best OS to use.

Dog-based OS is similarly as interesting as Puppy, but with a package manager that is more powerful than Puppy package manager, so you can expand its base OS, sky is the limit.

Void deserves a look for the adventurous and curious :
http://www.voidlinux.eu/

Some outstanding features :
Runit
runit is a simple and effective approach to initialize the system with reliable service supervision
Rolling release
Install once, update daily. Your system will always be up-to-date.
LibreSSL
We were the first distribution to switch to LibreSSL by default, replacing OpenSSL.
Due to the Heartbleed fiasco we believe that the OpenBSD project has qualified and pro-active developers to provide a more secure alternative.

xbps
xbps is the native system package manager, written from scratch with a 2-clause BSD license.

xbps-src
This builds the software in containers through the use of Linux namespaces, providing isolation of processes and bind mounts (among others). No root required!

For advanced users, the base iso is only 258mb (without a desktop environment, such as XFCE)
You need to install packages by yourself to have a complete desktop.

But common desktop environments are available as well :
mate, lxqt, lxde, xfce, cinnamon, enlightenment for both 32 and 64-bit systems. There are even ISO for Raspberry Pi as well.

These images need at least 256 or 512 MB of RAM in order to work correctly.

Void is right there alongside Puppy and Dog-based OS for users looking for a distro with small footprint and low ram usage.