Common File Extensions

Extention	Contents
.man	Unix manual page source
.encoding	Text in a particular encoding (e.g. .utf8)
.language-code	Text in a particular language (e.g. .de for German)
.lib	Library---collection of object files
.s	Assembly language source (Microsoft DOS / Windows, Unix)
.psp	Web server-executed source
.awk	Awk (language) source
.frm	Microsoft Visual Basic source
.com	MS-DOS/NT, OS/2 Rexx , VMS commands
.png	Microsoft Windows, X-Windows, portable bitmap file
.c	C source
.cpp, .cxx	C++ source
.cs	C# source
.class	Java compiled file
.sh	Unix csh, sh (Bourne) shell source
.def	Microsoft Windows or OS/2 executable or shared library definition
.so	Shared object library (Microsoft Windows, Unix)
.vbp	Microsoft Developer Studio project and workspace file
.dvi	Documentation in troff or TeX device-independent output
.el	Emacs lisp source
.tbl	Equations, pictures, tables to be typeset by eqn, pic, tbl
.Z	File compressed with gzip or compress
.h	C or C++ header file
.hpp	C++ header file
.icon	Microsoft Windows, X-Windows icon
.idl	Interface definition file
.info	Documentation generated by GNU Texinfo
.tar	File collection in Java, Unix shell, tape archive format
.java	Java source code
.jcl	IBM JCL instructions
.l	Lex (lexical analyzer generator) source
.m4	M4 (macro processor) code
.mk	Makefile (also often without any extension)
.mif	Documentation exported by FrameMaker
.me	Documentation using troff mm, me macros
.roff	Documentation in plain troff format
.obj	Object file
.ok	Local additions to the spell-check dictionary
.pod	Perl, module source, documentation
.ps	Postscript source, or formatted documentation
.py	Python source
.rb	Ruby source
.res	Microsoft Windows resource, compiled resource script
.sed	Sed (stream editor) source
.test	Test file
.tcl	Tcl/Tk source
.texi	Documentation in TeX or LaTeX, GNU Texinfo format
.y	Yacc (parser generator) source