Below is a link to the Equilibris Mod Community basically how I understand the mod is that it tries to balance HOMM: IV (I haven't had a chance to try it out yet) Also from what I've read tournaments from HOMM: IV this is a required mod.

http://equilibris.celestialheavens.com/eng/news.html

The only problem of this mod is that development of the next version has almost stopped, even the mod section on CH forums is quite dead.

I hope that the Heroes IV Equilibris 3.51 MOD is compatible with the GOG version. Maybe somebody could post a sticky of how to properly install it?

You have to download the installer plus first two files from here.
Extract the files to your Heroes 4 directory, install Equilibris and it's done.
You can play either with the mod or without, the game retains its functionality and mod adds its own shortcut on the desktop.

Sweet! Thanks Klaymen!

Might I suggest this thread be stickied? It'd be useful for those who're interested in a pretty huge mod for Heroes IV.

I mean, WoG has already been stickied, this one's of similar importance to Heroes IV

Has anyone still got a copy of this mod's installer on their hard-drive and could upload it? The links at the Equilibris website are dead

Celestial Heavens luckily has the file in their own download area (section "mods"):

http://www.celestialheavens.com/viewpage.php?id=567.

When I run that file, halfway through the install process an error pops up saying
"Warning! Your heroes4.exe file checksum isn't correct. \n You need to download special file from Downloads section of website to make mod work.
See FAQ section on http://strategyplanet.com/homm/equilibris/eng/faq.html"
The url goes to a 404.

Any idea how to fix this, or am I just too late to get everything required to make the mod work?

The FAQs have moved, too...question Q-07 here might adress your problem:

http://equilibris.celestialheavens.com/eng/faq.html

The file the answer says you should download can be find here:

http://equilibris.celestialheavens.com/eng/downloads.html

You find it under "Files", its the 2nd one. Click then the 2nd (not the FP one!) mirror, it will bring you to a russion site; there you can download the file.

Thanks for the info and links for the mod - this topic definitely should be stickied.

I was able to install it, but I cannot run it : getting Windows error.

Better look on this https://www.moddb.com/mods/greatest-mod

Yeah, unfortunately the latest version (Alpha one) has many incomplete / bugged content. I was hyped to download it but those "defects" made me change my mind. Will stay just with equilibris atm.

Tried instaling equiliris, it complained about checksum. Installed those 2 additional files, equilibris installed, checksum didnt come up, but it wont launc, it says missing important files. What can those be?
Just wanna play in hd or basically without the black boxes on both sides. If theres a simpler way of fixing it, would appreciate.