plus4emu - An open source emulator for Linux, MacOS, and Windows. - http://plus4emu.sourceforge.net/
WinEMU - A freeware C16/Plus4 emulator for DOS and Win32 platforms. Also contains game cheats and a developer section. - http://winemu.emuunlim.com/
Artifex - A freeware C16 and Plus/4 emulator for Windows. - http://artifex.emuunlim.com/
Minus4 - A freeware Plus/4 emulator for DOS, Java, and Windows. The Source Code for the Windows version is also available. - http://javalemmings.com/minus4/
C16-Plus4 Retro Page - Game downloads, computer history, tips and home of YAPE, A freeware C16 and Plus/4 emulator for Windows. An older open source version for Unix/SDL is also available. - http://yape.homeserver.hu/