2 file types use the .uop file extension.

What is a UOP file?

Presentation file created in the Uniform Office Format (UOF), an open document format created for Chinese office productivity applications; uses XML to describe the presentation and stores the presentation as a compressed archive.

More Information

Category: Data Files

Ultima Online Patch

A UOP file may also be a patch or update file used by the video game Ultima Online. It contains data the Ultima updater uses to update a player's Ultima Online client. While UOP files are not meant to be opened by players, Ultima Online enthusiasts have created utilities that allow them to edit UOP files.

Ultima Online is a massively multiplayer online role-playing game (MMORPG) published by Electronic Arts. In the game, players adventure through an open fantasy world, playing as warriors and mages.

Periodically, Electronic Arts distributes UOP files used to update players' game clients. The game typically installs these files automatically, and players do not need to interact with them. However, some Ultima Online modders enjoy extracting and modifying the data UOP files contain, to alter the game's appearance, sounds, and/or gameplay.

You can use UOFiddler (Windows) to convert a UOP file to the .MUL format. You can then use tools like MulPatcher to modify the file's contents, before using UOFiddler to convert the file back to the UOP format. (To use your modded UOP file, replace the default UOP file you modded with the new UOP file you created.)

Programs that open or reference UOP files

Updated: September 30, 2022