Dapplegrey is a frontend emulator for the MacOS X DOSBox port which emulates the MS-Dos and allows you to play all those old games you might be nostalgic for.
First of all though, you'll need a DOSBox Port which you can download from dosbox.com. Dapplegrey easily allows you to set configuration options for different games without having to mess around manually with Terminal or editing the DOSBox config file.
using Dapplegrey is like going back 20 years and reminds you how far computers have come since the days when graphics were just a few blocky pixels put together for fun. It's still a little tricky to work out and configure for an emulator newbie although there are some instructions on the developer website.
Dapplegrey is a fun emulator for all those that for some strange reason, hark back to the days of MSDOS.