DistroWatch - 9 hours ago - It does include a proprietary software set optimized for business users, students, researchers and developers." A list of features and further details can be found in the company's release announcement.
DietPi - Dietpi is a debian based operative system made to install new apps easyer.
SUSE Studio - Modernisieren Sie Ihre Infrastruktur mit SUSE Linux Enterprise Server, OpenStack Cloud-Technologie für IAAS und softwaredefiniertem Storage von SUSE.
TinyCore - Simple operating system based on Linux that uses "modules", and loads everything into RAM. Can be persistent too.
Puppy Linux - Home, overview and getting started with Puppy Linux, amazingly fast, fascinatingly complete and delightfully small Linux.Wiki · Download latest Puppy Linux .
DebianDog - DebianDog is very small Debian Live CD shaped to look and act like Puppy Linux.