DeSmuME is a Nintendo DS emulator
An emulator for Gameboy and GameboyAdvance systems
An advanced network simulator to design and configure virtual networks
Versatile Commodore Emulator
RetroArch is a frontend for emulators, game engines and media players.
The virtual serial port driver for Windows.
A cross-platform PSP emulator
A merge of the original Visual Boy Advance forks
A graphical environment for DOSBox
Nestopia UE
Local Terminal Emulator
A free, cross-platform emulator for GW-BASIC, PCjr & Tandy BASIC
Appliances of free/open source operating systems for VirtualBox
xBRZ: "Scale by rules" - high quality image upscaling filter by Zenju