C99 — Statistics

At a Glance

The Numbers

#1

TIOBE Index (2024)

52

Years since creation

15B+

Devices running C

30M+

Lines in Linux kernel

100%

CPU archs with C compiler

3

Mars rovers powered by C

Rankings

TIOBE Index — Language Popularity

The TIOBE index measures programming language popularity based on search engine queries. C has been in the top 2 for essentially the entire 25-year history of the index, winning "Language of the Year" in 2008, 2017, and 2019.

C

16.1%

Python

15.0%

C++

10.5%

Java

8.6%

C#

6.7%

JavaScript

2.9%

Source: TIOBE Index, approximate 2024 values. C has topped the index more times than any other language.

Scale

Lines of C Code in Major Projects

Project	Lines of C	What it does
Linux kernel	~30,000,000	Runs Android, servers, supercomputers, embedded, IoT, and 96.3% of the world's top 500 supercomputers
GCC	~15,000,000	The GNU Compiler Collection — compiles C, C++, Fortran, Ada, Go, and more
PostgreSQL	~1,500,000	The world's most advanced open-source relational database
SQLite	~250,000	The most deployed database in history — in every phone, browser, and OS
nginx	~190,000	Powers 34% of the world's web servers
Redis	~170,000	In-memory key-value store — caching backbone of modern web apps
CPython	~800,000	The reference implementation of Python
curl	~180,000	The most-used HTTP client library on Earth — installed on 10+ billion devices
Git	~400,000	The world's dominant version control system
OpenSSL	~500,000	TLS library securing most HTTPS connections on the internet
FFmpeg	~1,200,000	The multimedia framework behind nearly all video processing software
Vim	~380,000	The ubiquitous terminal text editor, installed on virtually every Unix system

Compilers

C Compiler Landscape

C has some of the most mature and aggressively optimizing compilers in existence:

GCC

GNU Compiler Collection. Since 1987. Default on Linux. Supports C89, C99, C11, C17, C23. Targets 70+ CPU architectures.

Clang/LLVM

Since 2007. Default on macOS/iOS. Superior error messages and static analysis. Powers AddressSanitizer, ThreadSanitizer, UBSanitizer.

MSVC

Microsoft Visual C++. Default on Windows. Full C17 support, partial C11. Integrated with Visual Studio.

TCC

Tiny C Compiler by Fabrice Bellard. Compiles C99 in milliseconds. Self-hosting. The entire compiler is ~100KB. Used for scripting-speed C compilation.

ICC / ICX

Intel C Compiler. Generates highly optimized code for Intel CPUs. Vectorization, OpenMP, and MKL integration for HPC workloads.

Emscripten

Compiles C to WebAssembly. Runs C code in the browser at near-native speed. Powers game ports, audio engines, and crypto libraries on the web.

Fun Facts

C By the Numbers

37

Keywords in C99

552

Pages in C99 standard

1978

First K&R book published

228

K&R pages (1st edition)

96.3%

Top-500 supercomputers run Linux (C)

10B+

Devices with curl (C)

1T+

SQLite databases in active use

2.5B+

Android devices (Linux kernel in C)

Perspective

Why These Numbers Matter

Languages like Python, JavaScript, and Go get the headlines. C gets the infrastructure. Every Python script runs on CPython (C). Every JavaScript app runs on V8 (C++) which links against libc (C). Every Go binary is compiled by a compiler that was bootstrapped from C.

C is not competing with other languages. C is the substrate on which other languages exist. When you measure C's usage, you're not measuring popularity — you're measuring the foundation of computing itself. And foundations don't trend on Twitter. They just work, silently, forever.