ANSI C

Software developers writing in C are encouraged to conform to the standards, as doing so helps portability between compilers.

[1] While some software developers use the term ISO C, others are standards-body neutral and use Standard C. Informal specification in 1978 (Brian Kernighan and Dennis Ritchie book The C Programming Language).

Aside from error correction there were further changes to the language capabilities,[6][7] such as: In addition to the amendment, two technical corrigenda were published by ISO for C90: In March 2000, ANSI adopted the ISO/IEC 9899:1999 standard.

GCC and Clang are two major C compilers popular today, both based on the C11 with updates including changes from later specifications such as C17.

[29][30] Any source code written only in standard C and without any hardware dependent assumptions is virtually guaranteed to compile correctly on any platform with a conforming C implementation.

Note how this code checks both definition and evaluation: this is because some implementations may set __STDC__ to zero to indicate non-ANSI compliance.