MDI Viewer

MDI Viewer is a very basic Windows utility that was designed with a single goal in mind: allow you to view MDI files with just a few clicks.

Plain GUI and file types you can open

And because everything has been designed to be very simple, the interface is far from being eye-candy or appealing. It is just the classic way to let you open an image file with absolutely no other menu or configuration screen.
Besides support for MDI files, MDI Viewer is also compatible with a few other image formats, including JPG, BMP, GIF, PNG and TIFF, so the application can very well be used as a universal image viewer.

Support for all Windows editions and accessibility for all users

Unfortunately however, MDI Viewer is far from what you may expect, relying on very basic components, including interface and features.
As you can see, everything's very simple within MDI Viewer, so beginners should have absolutely no problem when using the application, yet the developers have still included a Help file to provide more information on the application.
Just as expected, you do not need a very fast computer to run the application and it remains very friendly with computer resources all the time, no matter the Windows version installed on a given computer.

Conclusion

Overall, MDI Viewer may come in handy to some of the users out there, yet the application simply lacks too many features to become a top product in this particular software segment. An interface update, as well as more features and a detailed customization screen are absolutely mandatory for such an app.
Not to mention that an image viewer needs file associations tools, especially when talking about a program that's designed to handle just a specific type of file.