The Surprising Places C Language Is Used in 2025

Despite C++ being used in millions of games, the C language is only about 2.7% less popular. Today, C remains a cornerstone in numerous critical fields, proving its enduring relevance. This article explores the various domains where C continues to be indispensable.

Powering Critical Infrastructure

One of the most significant applications of the C language is in election vote-counting machines. The majority of these systems rely on C, with only a few using assembly language. The reason for this choice is that low-level languages like C provide direct access to hardware components, ensuring reliability and precision.

The Language of Robotics

When you see robotic arms in modern factories, you might wonder what language powers them. While many robotics companies have developed proprietary programming languages or use robot-specific ones like Inform, Karel, or RAPID, there's a common thread: most of these languages share a syntax similar to C. This design choice leverages the efficiency and control that C-like structures offer.

Innovations in Medical Technology

The C language plays a vital role in the medical industry, a field where precision can be a matter of life and death.

• BlackBerry QNX: You might remember BlackBerry for its iconic mobile phones with physical keyboards. Today, the company has pivoted to creating products for the medical industry under the name BlackBerry QNX. QNX is a microkernel operating system built using C and C++, and applications for this OS must also be coded in one of these two languages.
• Johnson & Johnson: The well-known consumer goods company also develops medical software. Historically, they used the C programming language for their solutions. However, they are now shifting their focus, with current hiring trends indicating a complete transition from C to C++.

The Foundation of Modern Operating Systems

C is the bedrock upon which modern computing is built. Major operating systems, including Linux, Windows, and macOS, which are installed on approximately 1.8 billion computers worldwide, have significant portions of their architecture written in C. While not built entirely in C, the core components that manage system resources and hardware are often implemented in this powerful language.

Reaching for the Stars: C in Space Exploration

The C language is trusted for missions where failure is not an option.

• NASA's Mars Curiosity Rover: The flight software for this famous rover, a project with a budget of $2.52 billion, was developed using C. In an interesting turn of events, a few months after landing on Mars, the rover encountered technical issues. The engineering team solved the problem with a simple reboot, a testament to the robust nature of the system. In addition to C, these robotic missions also use MATLAB for data analysis and simulations.
• European Space Agency (ESA): The software for the ESA's Rosetta mission, designed to study a comet from orbit, was also written in C. This demonstrates that from our planet to the far reaches of the solar system, C is a language of choice for space exploration.

Controlling Our World: From Roads to Skies

C's ability to interact closely with hardware makes it ideal for controlling a wide range of transportation and navigation systems.

• Traffic Management: Many traffic light controllers use C to manage the timing and sequence of signals, ensuring a smooth flow of vehicles.
• Automotive Systems: C controls your car not just from the outside but from the inside as well. It is used in numerous automotive systems, including Anti-lock Braking Systems (ABS) and Engine Control Units (ECU).
• Aviation: The flight control software for advanced aircraft like the F-22 Raptor is written in C.
• Maritime Navigation: OpenCPN, an open-source maritime chart plotter and navigation software, is used in ships to manage systems and navigate safely. An inspection of its GitHub repository reveals that the project is written almost entirely in C.

From the roads we drive on to the water we navigate and the skies we fly, the C language is a silent yet powerful force that governs our world.