C Standard (ISO/IEC 9899)

1. Language basics

   Types, declarations, expressions, statements and the preprocessor.

2. Types and objects

   Fundamental types, integer promotions and object representation.

3. Pointers and arrays

   Pointer declarations, arithmetic and arrays.

4. Undefined behavior

   Defined, implementation-defined, unspecified and undefined behavior.

5. Preprocessor

   Macros, conditional inclusion and #include.

6. Memory management

   malloc, calloc, realloc, free and alignment.

7. Strings

   Null-terminated byte strings and multibyte strings.

8. File input/output

   stdio streams and formatted I/O.

9. Concurrency and atomics

   Threads, mutexes and condition variables in C11.

10. Atomic operations

    Atomic types and memory orders.

11. Standard library headers

    Standard library header index.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.