Originally expected to be a simple balance pass with only minor tweaks, version 4 quickly snowballed into a near-total overhaul of the whole mod. Every unit was included in the balance pass, a bunch of graphics were overhauled, the entire skirmish AI lineup was replaced with brand new ones and the setup screen was rearranged, plus a bunch more stuff you'll have to check the huge change log to find out about!
You can download the mod from the files page here.
Also included in the mod's readme are instructions on how to get online multiplayer working via a tunneling service. This method isn't guaranteed, but from limited testing it seems to work just fine. It does involve messing around with the contents of your game's directory so the readme instructions were made as detailed as possible, hopefully that helps everyone that's tried to get it working over the last few years.
Anyone who plays with a widescreen monitor - which is most people these days I imagine - should also pick up the Widescreen UI fix which will work with both Reversal and the original game. There's also an Intro Skip addon if anyone's interested in that, again compatible with both.
And for anyone that's managed to miss it until now, remember there's a large collection of custom maps available in the map pack which you can download from here.
Enjoy!