Ctags是一个用于从进程源代码树产生索引文档（或tag文档)，从而便于文本编辑器来实现快速定位的实用工具。在产生的tag文档中，每一个tag的入口指向了一个编程语言的对象。这个对象可以是变量定义、函数、类或其他的对象。

Ctags是开放源代码的进程。支持下列的编程语言：汇编，AWK, ASP, BETA, Bourne/Korn/Zsh Shell, C, C++, COBOL, Eiffel, Fortran, Java, Lisp, Lua, Make, Pascal, Perl, PHP, Python, REXX, Ruby, S-Lang, Scheme, Tcl, Vim, and YACC。

Ctags is a programming tool that generates an index (or tag) file of names found in source and header files of various programming languages. Depending on the language, functions, variables, class members, macros and so on may be indexed. These tags allow definitions to be quickly and easily located by a text editor or other utility. Alternatively, there is also an output mode that generates a cross reference file, listing information about various names found in a set of language files in human-readable form.