Frontends

BOSS MSX Frontend - http://members.ams.chello.nl/koppejan/
Frontend for the fMSX emulator.

EMUStation - http://zerosoft.zophar.net/emustation.htm
Universal Frontend, featuring built-in IPS patcher, ZIP support, and Explorer integration.

Game Launcher - http://www.dribin.org/dave/game_launcher/
A universal DOS front end for emulators.

GameBoy Mnu - http://www.geocities.com/Area51/Dimension/9532/
Frontend for GameBoy 97

Genesis LaunchTool - http://www.classicgaming.com/launchtool/
Header tool and launcher for Genesis emulators.

Hyper Em - http://www.classicgaming.com/hyperem/
Win32 graphical frontend for any command line launched emulator.

Kemulator - http://kemulator.sourceforge.net/
A multi system open source frontend for Linux/KDE.

KStella - http://kstella.sourceforge.net/
A KDE frontend to the Atari 2600 emulator, Stella.

Raging Dragon - http://www.oscarcontrols.com/dragon/
Skinable front end for MAME, Impact and Modeler.