NXC stands for Not eXactly C.

It is a simple language for programming the LEGO MINDSTORMS NXT product. The NXT has a bytecode interpreter (provided by LEGO), which can be used to execute programs. The NXC compiler translates a source program into NXT bytecodes, which can then be executed on the target itself. Although the preprocessor and control structures of NXC are very similar to C, NXC is not a general-purpose programming language - there are many restrictions that stem from limitations of the NXT bytecode interpreter.

Logically, NXC is defined as two separate pieces. The NXC language describes the syntax to be used in writing programs. The NXC Application Programming Interface (API) describes the system functions, constants, and macros that can be used by programs. This API is defined in a special file known as a "header file" which is, by default, automatically included when compiling a program.

This document describes both the NXC language and the NXC API. In short, it provides the information needed to write NXC programs. Since there are different interfaces for NXC, this document does not describe how to use any specific NXC implementation (such as the command-line compiler or Bricx Command Center). Refer to the documentation provided with the NXC tool, such as the NXC User Manual, for information specific to that implementation.

For up-to-date information and documentation for NXC, visit the NXC website at http://bricxcc.sourceforge.net/nxc/.