If you are wondering what EUI is...
If you have fallen for civ5 (like I have) and are new to mods (like I am) then you may be wondering what EUI is, how to get it and is it worth it.

EUI's full name is Civ5 Enhanced User Interface. You can't get it from Steam because, according to the author, he was not able to get a "Firaxis key". And so you have to get EUI from civfanatics.com and manually download and install it. Here is the link: https://forums.civfanatics.com/resources/civ5-enhanced-user-interface.24303/

Alternatively, you can Google "civ5 EUI".

The present version, as Gaia implies, is v1.29h which she says is not compatible. So, go to that civfanatics page and click on the History tab and you'll see a Download button to the far right of the 1.28g entry. Be prepared to CAREFULLY follow the install directions...it will involve creating and moving around folders.

What does EUI do and is it worth installing? Well, I have not used it myself yet but judging by its popularity I would guess yes. Its good enough for Gaia to have made a separate mod for it. What this mod does is enhance menus, tool tips and mouse overs. We all know how info intensive the Civ games can be, and the bigger our empires are the more of a pain this info can be to handle. EUI, according to it's write-up, makes things easier. It does not, however, change gameplay. No new units or structures or systems. Its just better information management.