If you just want to play it, you can get a plugin for Winamp called AdPlug that supports DRO files.

If you want to edit it, your options are limited. There's an old editor floating around on the net called DRO-ED, unfortunately it expects an old version of the file format, and saves it to a proprietary version of the file format that is not recognised by anything. If you feel like getting technical, you can get it to read more recent dumps through a bit of hex editing (I think you need to change the DRO format version number from 4 bytes to 1).

However, I have made a simple little tool called "DRO Trimmer" that I will be releasing to these forums sometime soon (I need somewhere to put it, first). It is pretty unsophisticated, but it will let you delete any instructions you desire. It also has the ability to try to detect looping portions in a song, but this doesn't work very well.

If you want to view/edit it like MIDI, well, that's pretty much unfeasible. There are oldschool Adlib trackers out there, but they save in their own formats (e.g. I know Scream Tracker 3 can let you make OPL/Adlib songs), and they require DOS (not so much a problem). None of them support DRO files.

tell your computer to monitor wave out and then just use windows sound recorder in conjuncion with dosbox to record stuff as wave files... its what i do usually for programs with odd ball music formats.