Dblscan by Mark Russinovich and Bryce Cogswell

Summary of directory contents:

gui: the source code (MSVC 1.51) for dblscan's user interface
vxd: the source code (vtoolsd for Windows 3.1) for dbscan's vxd
release: readme on how to run and interpret dblscan results plus
     files showing screen-shots of experiment's run on the most
     popular RAM compression products

