Altair32
   An open source Altair emulator for Windows.
   http://www.altair32.com/

CP/M
   An open source CP/M-80 ver2.2 emulator for MacOS.
   http://homepage3.nifty.com/bugbug/cpm/

Desktop Cyber
   An open source CDC (Control Data Corporation) Cyber 6x00, 7x or 17x type mainframe emulator for Windows or Unix.
   http://members.iinet.net.au/~tom-hunter/

Emu28
   An open source HP18C/28C emulator for Windows.
   http://hp.giesselink.com/emu28.htm

Emu48
   An open source HP38/39/40/48/49 emulator for Windows.
   http://hp.giesselink.com/emu48.htm

Emu51
   An open source 8051 emulator for Linux and Windows.
   http://emu51.sourceforge.net/

EmuLTI 8
   An open source Mitsubishi Multi 8 for Windows and Windows CE.
   http://www1.interq.or.jp/~t-takeda/multi8/

EmuPIA
   An open source Toshiba Pasopia emulator for Windows and Windows CE. [English/Japanese]
   http://www1.interq.or.jp/~t-takeda/pasopia7/

Emula3
   Contains emulators for many different computers and calculators/PDAs for many different platforms. [English/Italian]
   http://www.emula3.com

Emuviews
   Great emulation page maintained by JoseQ, maker of the famous Rumor Mill, many downloads, great layout - some hosted sites.
   http://www.emuviews.com/

Evenson Consulting Services' SWTPc 6800/6809 Emulator
   Windows 9x/NT GUI emulation of SWTPc 6800 and 6809 systems. A Simulated Machine Environment (SME) emulation plus .dsk file downloads.
   http://www.evenson-consulting.com/

FunnyMu
   A freeware Creativision, Funvision, and Whizzard emulator for Linux/SDL.
   http://www.lemoncube.com/26.html

GXemul
   An open source MIPS machine emulator for Linux.
   http://gavare.se/gxemul/

HiRISC Simulator
   A freeware emulator for Windows of a system designed specifically for the Applied Systems Programming course at the University of Akron.
   http://www.cs.uakron.edu/~margush/307_Old/HiRISC/

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.
   http://www.jcec.co.uk/

KCemu
   An open source emulator of the KC85 homecomputer series for Linux and Windows.
   http://kcemu.sourceforge.net/

Newbrain Emulator Pro
   A freeware Grundy NewBrain emulator for Windows written in Delphi.
   http://newbrain.1111mb.com/

PearPC
   An open source PowerPC emulator for Unix and Windows.
   http://pearpc.sourceforge.net/

Project8080
   Covers the development of a Heathkit H8 emulator on Macintosh.
   http://davidwallace2000.home.comcast.net/h8/project8080_archive/

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.
   http://simh.trailing-edge.com/

SPRINT
   A freeware Sprinter emulator for Linux/i386 and Windows.
   http://www.nedopc.org/nedopc/sprinter/sprint.shtml

Solace
   An open source Sol-20 emulator for Windows.
   http://www.sol20.org/solace.html

TinyELF
   A freeware emulator of CDP1802 based microcomputers for Mac OS X.
   http://homepage.mac.com/ruske/tinyelf/

Virtual Alpha Micro
   An open source AM-100 micro computer emulator for Cygwin, Linux, and Mac OSX.
   http://www.otterway.com/am100/

XRoar
   An open source Dragon 32/64 and Tandy CoCo emulator for Linux , MacOS/PPC, GP32, and Windows.
   http://www.6809.org.uk/dragon/xroar.shtml

blueMSX
   An open source SVI318/328, MSX1, MSX2, MSX2+, and Turbo-R emulator for Windows.
   http://www.bluemsx.com/

cinc
   An open source Bell Labs cardiac emulator for Linux and Windows/Cygwin.
   http://sourceforge.net/projects/cinc/

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]
   http://www.ontko.com/mic1/

st20emu
   A freeware ST20 emulator for DOS.
   http://sourceforge.net/projects/st20emu/

uBee512
   Open source Premium Microbee 512Kb FDD emulator for Linux and Windows.
   http://sourceforge.net/projects/ubee512/

vmips
   An open source MIPS R3000 emulator for Unix.
   http://vmips.sourceforge.net/