From IFWiki

C (pronounced "see") is a general purpose programming language developed by Bell Telephone in the early 1970s. It is known as a highly portable language; a C program can be written once and then compiled with either no or minimal changes on most of the commonly used computer systems.

Although a handful of text adventures have been written in C, the language is more commonly used by the IF community for creating utility programs, especially compilers and interpreters.

The derived languages C++ ("C plus plus") and C# ("C sharp") have also been used to create utility programs.

C's look-and-feel also influenced the design of TADS and, to a lesser extent, the first versions of Inform.

Further reading