NEO4ALL is an alternative Open Source NEOGEO/CD emulator for the Dreamcast console by Chui&Fox68k. Features:

Close to fullspeed emulation (frameskip0 with sound-fx).

Fast FAME Motorola 68000 core by Fox68k.

MAME Z80 core.

Custom PowerVR2 graphic core (fast tile caching).

Autoframeskip for real speed.

Joystick is emulated with analog and digital pad + A,B,X,Y and Start/R-Trigger.

Complete menu with L-Trigger: region selector, frameskip control, graphic filtering, hardware reset…

Crystalline sound without lag.

Both control players emulated.

A lot of games work.

http://chui.dcemu.co.uk/neo4all.html