D2DX is a complete solution to make Diablo II run well on modern PCs, with high fps and better resolutions.
Thanks to @pairofdocs for submitting a nice video clip that showcases the high-fps features in D2DX. (It's on the main page/linked from the README.)
Unlock FPS in menus. (Known issue: char select screen animates too fast)
Add experimental "sleep fix" to reduce microstutter in-game. Can be enabled with -dxtestsleepfix. Let me know if you notice any improvements to overall smoothness in-game, or any problems!
NOTE: The -dxtestmop option has been removed. Instead, if you prefer the old 25fps gameplay you can opt out of using it by specifying -dxnomop (or setting nomotionprediction to true in the config file).