Mednafen
Emulates:
NES
Atari Lynx
PCE & PCE-CD
PC-FX
NGPC
GB/GBC/GBA
"Sleeeeep, braaaaaiiins.
Read the ChangeLog, ChangeLog is good! This release as a whole should be considered beta-quality, since so many core changes have been made. PC-FX emulation in this release is very pre-alpha-ish, but it does work with a couple of games(yay Chip Chan Kick), though without FMV...but you do need a dump of the PC-FX's BIOS ROM, which I won't provide, so you'll just have to write a program and burn it to a CD-R to dump the BIOS ROM using pulse-width modulation sound output like I did, nyaaaah~
A few happy additions:
Button settings saved in plain-text mednafen.cfg file. No more evil inputmap.cfg!
Better network play console. FEEL the fuzzy networking.
Support for 6-button PC Engine gamepad emulation.
Support for PC Engine mouse emulation. If you're smart, you can play 2-player Lemmings with mice over netplay...probably. ^_^
New internal font!
More sound drivers(ALSA and jack) available for UN*X.
Short help screen by pressing F1 screen."
Download Mednafen 0.7.0 from here
LinuxEmu
http://linuxemu.retrofaction.com/article.php?story=20061222042039513