The Common Open Research Emulator (CORE) is a tool for emulating networks on one or more machines. You can connect these emulated networks to live networks. CORE consists of a GUI for drawing topologies of lightweight virtual machines, and Python modules for scripting network emulation.
OsnofianLinux is a set of small distributions intended to fit on 1.44Mb floppy disk, in the boot sector of a CDROM, hard drive or even on a USB stick. Check the project homepage for more details and projects info.