cinc An open source Bell Labs cardiac emulator for Linux and Windows/Cygwin.
Emuviews Great emulation page maintained by JoseQ, maker of the famous Rumor Mill, many downloads, great layout - some hosted sites.
Japanese Computer Emulation Centre A site dedicated to the emulation of Japanese Machines including X68000, PC6001, PC88, PC98, MSX 1/2/R, Sharp MZ, Sharp X1, Fujitsu FM7, and Fujitsu FM Towns.
Desktop Cyber An open source CDC (Control Data Corporation) Cyber 6x00, 7x or 17x type mainframe emulator for Windows or Unix.
mic1 A Java-based simulator which implements the Mic-1 microarchitecture described in Chapter 4 of Andrew S. Tanenbaum, Structured Computer Organization, Fourth Edition. [Open source, GPL]
Flexemu An open source EurocomII/V7 emulator for Linux and Windows.
Emu51 An open source 8051 emulator for Linux and Windows.
SIMH An open source collection of emulators for Windows of historical computers, including GRI-909, HP 2116/2100/21MX, IBM 1401/1620/1130/System 3, PDP-1/4/7-11/15/VAX. Also provides software kits, system photographs, and technical papers.
CP/M An open source CP/M-80 ver2.2 emulator for MacOS.
KCemu An open source emulator of the KC85 homecomputer series for Linux and Windows.
FunnyMu A freeware Creativision, Funvision, and Whizzard emulator for Linux/SDL.
Emu28 An open source HP18C/28C emulator for Windows.
Virtual Alpha Micro An open source AM-100 micro computer emulator for Cygwin, Linux, and Mac OSX.
TinyELF A freeware emulator of CDP1802 based microcomputers for Mac OS X.
GXemul An open source MIPS machine emulator for Linux.
PearPC An open source PowerPC emulator for Unix and Windows.
blueMSX An open source SVI318/328, MSX1, MSX2, MSX2+, and Turbo-R emulator for Windows.
HiRISC Simulator A freeware emulator for Windows of a system designed specifically for the Applied Systems Programming course at the University of Akron.
SPRINT A freeware Sprinter emulator for Linux/i386 and Windows.
XRoar An open source Dragon 32/64 and Tandy CoCo emulator for Linux , MacOS/PPC, GP32, and Windows.
EmuPIA An open source Toshiba Pasopia emulator for Windows and Windows CE. [English/Japanese]
EmuLTI 8 An open source Mitsubishi Multi 8 for Windows and Windows CE.
Solace An open source Sol-20 emulator for Windows.
Altair32 An open source Altair emulator for Windows.
Newbrain Emulator Pro A freeware Grundy NewBrain emulator for Windows written in Delphi.