What does the acronym GCC originally stand for in the context of C programming?

GCC originally stood for GNU C Compiler.

When the GNU Project first released the compiler in 1987, it was designed to compile the C programming language, so the name accurately described its purpose. Richard Stallman began the project as part of the effort to build a complete free operating system and toolchain. GCC quickly became important to Unix-like systems because developers could use, study, modify, and redistribute it under the GNU General Public License.

The compiler’s scope expanded rapidly. C++ support arrived in 1987, and later front ends were added for languages including Objective-C, Fortran, Ada, Go, and others. Because it was no longer only a C compiler, the project was renamed the GNU Compiler Collection. The initials GCC were retained.

That history explains the tempting wrong answer GNU Compiler Collection: it is the modern official expansion, but not the original one asked for here. GCC is also sometimes casually called “the GNU compiler,” while gcc is the command-line driver commonly used to compile C programs. The driver may invoke preprocessing, compilation, assembly, and linking, depending on the command options.