Open O file

O files: what are they and how do I open them?

o file icon Are you facing difficulties opening unknown files on your computer, or wondering exactly what this file is?
We've got the information and best software solutions for opening these files effortlessly.

.o file type #1: Various objects

The object file format, primarily associated with various programming languages and development environments, is typically denoted by files with o extension.

Further details:

An .o file, also known as an object file, is a file that is created when a source code file is compiled by a compiler. It contains machine code, but is not yet an executable file.

The object file contains the compiled source code along with additional information such as debugging symbols and references to other pieces of code that the compiled code calls upon. These .o files are then linked together by a linker to create an executable file. This process allows for separate compilation of source files, which can speed up the development process. The .o file format is used in various programming languages, including C, C++, and Assembly.

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Microsoft Visual Studio icon

Microsoft Visual Studio

IDE for creating programs, or websites and web applications


A set of data analysis and graphing tools

Xcode icon


IDE used for development of app in Objective-C programming language

Free Pascal

A professional Pascal compiler

.o file type #2: UFO: Enemy Unknown game data

Files with o file suffix are associated with the UFO: Enemy Unknown game data format.

Further details:

The o file extension is related to the UFO: Enemy Unknown (also known as X-COM: UFO Defense), a sci-fi turn-based strategic video game for MS-DOS and Amiga.

The o file stores some kind of game data.

There is original version of UFO: Enemy Unknown running on Microsoft Windows via DOSBox available to purchase on Steam distribution service.

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X-COM: UFO Defense (UFO: Enemy Unknown) icon

X-COM: UFO Defense (UFO: Enemy Unknown)

Turn-based strategic computer game

What is the meaning of a file extension?

File extensions are characters that appear after the dot in a computer file's name. For example, the file "unknown-file.o" has the file extension "o". This is used to identify which program should open the file or what file type it is.
File extensions help you organize and manage files. They provide a quick and easy way to identify and associate the file type with the appropriate software.

We can help you open your file

In our database, we have collected a huge number of different file extensions, detailed descriptions, and programs that can be used to open or otherwise work with the file extensions listed in our database.
This database is an invaluable resource for users who want to understand better file extensions and what they can do with them. It also allows users to know different file types with the same purpose.

Only verified software links are provided

We have verified every software listed in our database. The software listed in our database includes links to the developer's or software's website. These links should allow you to download the right program for each file type. Using verified software from reputable sources helps minimize the risk of malware and viruses infecting your computer.