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C remains widely used across systems, embedded, and performance-critical software.
C23 introduces new features while older standards remain widely used.
Linux kernel development continues relying heavily on C alongside Rust.
C may be one of the oldest widely used programming languages, but it remains firmly embedded in modern computing. From operating systems and embedded devices to performance-critical applications, C is preferred where direct control over memory, hardware, and system resources matters.
The language is also evolving. The current C standard, C23, was adopted by ISO and IEC in 2024 as ISO/IEC 9899:2024. The standardization process is underway with the next version, referred to as C2y, coming soon.
The Linux kernel is one of the clearest examples of C’s continuing role in systems programming. Linux kernel documentation states that the kernel is written in C and is typically compiled with GCC using the GNU C11 dialect. Clang is also supported.
Linux is not limited to C. The kernel also supports Rust under CONFIG_RUST, with Rust code compiled using rustc and the 2021 edition. The addition of Rust reflects the changing systems-programming space, but C remains central to the kernel’s development.
This continued use matters because systems software sits close to the hardware and often has strict requirements around memory, execution, and resource management.
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C allows programmers to access memory and data representation without making the language too bulky.
These qualities have helped make C particularly applicable to OSes, device drivers, firmware, runtimes, and other low-level systems components.
Moreover, the C standards body describes C as a general-purpose language that can be used for system programming.
The documentation of C also specifies that the language has been compiled on a vast array of computers and operating systems and extensively cross-compiled for embedded systems.
Embedded development remains another important area for C. Firmware frequently needs to communicate directly with registers, peripherals, memory, and other hardware interfaces.
The international standards process continues to maintain work related to Embedded C, reflecting the language’s ongoing connection with embedded development.
The 2025 JetBrains State of C report, based on responses from almost 900 C developers across 23 countries, also found that C remains in use across embedded systems, legacy modernization, and high-performance applications.
Also Read: The Decline of C Programming: What’s Replacing It?
C is also widely associated with performance-critical software because developers can exercise detailed control over memory allocation, data structures, and system resources.
This does not mean C programs are automatically faster than programs written in other languages. Performance depends on algorithms, compiler optimization, hardware architecture, and implementation details.
However, C’s low-level model gives developers significant control when predictable resource use and efficient execution are important.
The C standard itself lists portability, reliability, maintainability, and efficient execution among the purposes of the standard.
C has not remained unchanged while newer programming languages have emerged. C23, published in 2024 as ISO/IEC 9899:2024, introduced several changes to the language.
These include bit-precise integers, decimal floating-point types, binary integer constants, digit separators, and new attributes. C23 also introduces static_assert and thread_local keywords while removing or deprecating some older features.
Compiler support is also moving forward. GCC documentation identifies C23 as the fifth version of the C standard and states that support can be enabled with -std=c23 or -std=iso9899:2024. GCC’s default C dialect is now gnu23.
Some software engineers still use older versions of C23. According to a JetBrains survey of 2025, 17% used C23, up from 4% in 2023, while 21% used C17/C18. C99 was the most common version, at 42%, while 36% used C11. Meanwhile, 21% of respondents used Embedded C.
C remains relevant not because a new, more advanced language will replace it. Instead, it remains part of the computer system development ecosystem, where each language fulfills a specific role.
The continued use of C in the Linux kernel, its history in embedded systems, direct access to system resources, and the ongoing improvements in C23 explain this phenomenon.
C skills will be useful in 2026 and beyond when developing an operating system, firmware, and interfacing with hardware devices.
Why is C programming still important in 2026?
C remains important for systems, embedded, and performance-critical software requiring low-level control, efficient execution, and predictable resource usage.
What is C23?
C23 is the latest C standard, published in 2024, introducing features including bit-precise integers, attributes, and binary integer constants.
Is C still used for embedded systems?
Yes, C continues to support embedded development, where software frequently interacts directly with hardware, memory, registers, and peripheral devices.
Does C provide better performance than other languages?
C provides low-level control, but actual performance depends on algorithms, compiler optimization, hardware architecture, and implementation quality.
Is C used in Linux kernel development?
Yes, the Linux kernel is written in C, while Rust is also supported for certain kernel development components.
