Dosbox is a full x86 emulator written in C/C++ with sound and dos. It's main use is to run old dosgames on platforms which don't have dos (win2k/XP/FreeBSD/linux). The most important new features: namemangling, cdrom support, scale2x, midi, improved timing, lots of bugfixes.
Also take a look at our new homepage:
which includes a list of working games