First, what is Open UI?

Open UI is a Look and Feel set of Modules that Looks and Feels exactly like the MMUI Look and Feel.  Open UI replaces the mmui.mv module with a set or group of modules.  The oui.mv file and one file for each Screen or Function in the mmui.mv file.

If it looks and feels just like MMUI why should I change?

Periodically, Miva upgrades the Miva Merchant program.   If you have made any changes to your mmui.mv file, you lose them when you upgrade.  This means you either have to make all of the changes to the new version if you are adept with Miva Coding or, if not, pay someone else to make the changes for you.

How does Open UI solve this problem?

In Open UI, all changes are made as Extension Modules.  Although they are hooked to the Open UI modules they are completely independent files.  Whether you upgrade Miva Merchant or the Open UI, your changes remain intact.

What if I do not know how to write Extension Modules?

If you cannot write Extension Modules you probably cannot edit your mmui.mv file either.  This means you will have to pay someone to make the changes for you.

With Open UI there are many Extension Modules available that are either free or very inexpensive.  OUI Extension Modules are simple to install, no coding required. 

An addition, almost all Third Party Modules have been upgraded to OUI.  This means no coding required to install them either.

And, even if you pay someone to create a special purpose Extension Module, you are only going to pay for it once.