MMO File

What are MMO files and how to open them

Are you having problems opening a MMO file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your MMO files.

What is a MMO file?

MMO files have multiple uses, and Hyper File Memo is one of them. Read more about the other uses further down the page.

Hyper File Memo

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open MMO files

Important: Different programs may use files with the MMO file extension for different purposes, so unless you are sure which format your MMO file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested three different MMO openers which you will find listed below.

Last updated: August 10, 2026

All known file formats using extension .MMO

While Hyper File Memo is a popular type of MMO-file, we know of 6 different uses of the .MMO file extension. Different software may use files with the same extension for different types of data.

Memory-Map Navigator Overlay

Memory-Map Navigator Overlay files store map overlay information created by the Memory Map PC mapping and navigation software. These binary files are written internally by the Memory-Map Navigator program to save things like routes, GPS tracks, waypoints, categories, icons, and text over a base map. The overlay data is used to let the software display and organize user-placed marks, paths, and text objects atop map images. These files are for the PC version only; mobile apps for Android, iOS, and Mac use GPX when importing or exporting overlay data.

When you're using Memory-Map Navigator, every time you draw a route, drop waypoint markers, record tracks, place text annotations, or assign categories, those overlay objects are saved into an MMO file. The program reads these files to re-display your overlay objects when you reopen the map later. Because MMO is proprietary and not backward-compatible between versions, plugins or users with older releases may not be able to open newer MMO files and should export data to GPX if sharing.

Files in this format normally include internal identifiers and keywords, enabling detection by signature. For example, at offset 2 the bytes 0xFFFF often appear, and ASCII-strings like "CObjIcons.Unnamedobject", "CCATEGORY", "COBJICONS", or "UNNAMED OBJECT" may be found inside. These identifiers reflect overlay objects such as icons, categories, or unnamed items.

MMO opener for Windows

We have identified one MMO opener that is compatible with this specific type of MMO file.

Mesen Movie

We know that one MMO format is Mesen Movie. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Micro Magic Forms In Flight Objects

We know that one MMO format is Micro Magic Forms In Flight Objects. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

RapidFile Memo

We know that one MMO format is RapidFile Memo. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

WINDEV HFSQL Memo

We know that one MMO format is WINDEV HFSQL Memo. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of MMO files. Remember, different programs may use MMO files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about MMO file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.