Code

Files that hold programs, or the text and instructions they are built from: source code, bytecode for virtual machines, compiled programs and libraries, object files, debug information, firmware, notebooks, shaders, build files and packages.

Groups

Source code

Programs as people write them, in plain text.

3 formats

Bytecode

Compiled instructions for a virtual machine rather than a real processor.

3 formats

Programs & libraries

Compiled machine code that the operating system loads and runs.

5 formats

Object files

Compiled code waiting to be linked into a program or library.

1 format

Debug info

Maps from compiled code back to source lines, names and types.

1 format

Firmware & ROMs

Images of code and data for chips, consoles and devices.

2 formats

Notebooks

Code, its results and notes together in one document.

1 format

Shaders

Programs that run on the graphics card.

1 format

Build files

Instructions for building a project from its source.

1 format

Packages & installers

Programs bundled with everything they need to install.

4 formats

All code formats

Format	Name	About
Source code
`.C`	C source code	Programs in the C language as plain text, with .h headers.
`.JS`	JavaScript source code	Scripts and modules for browsers, Node.js and other runtimes.
`.PY`	Python source code	Python programs and modules as UTF-8 text.
Bytecode
`.CLASS`	Java class file	One compiled Java class: a constant pool, fields and JVM bytecode.
`.PYC`	Compiled Python bytecode	Python’s cache of a compiled module: a version header and a code object.
`.WASM`	WebAssembly module	Portable bytecode for browsers and runtimes, in numbered sections.
Programs & libraries
`.DYLIB`	Mach-O executable and library	Programs, .dylib libraries and universal binaries on macOS and iOS.
`.ELF`	Executable and Linkable Format	Programs, libraries and object files on Linux and Unix systems.
`.EXE`	MS-DOS executable (MZ)	16-bit DOS programs: an MZ header, relocations and the code.
`.EXE`	16-bit Windows executable (NE)	Windows 3.x and early OS/2 programs and DLLs, in movable segments.
`.EXE`	Windows Portable Executable (PE)	32-bit and 64-bit Windows programs and DLLs: headers, sections and imports.
Object files
`.OBJ`	COFF object file	Compiled code from Windows compilers, waiting for the linker.
Debug info
`.PDB`	Microsoft program database	Debug symbols for Windows programs, in numbered streams.
Firmware & ROMs
`.HEX`	Intel HEX firmware	Firmware as lines of hexadecimal records, each with an address and checksum.
`.NES`	iNES ROM image	NES cartridge images for emulators: a 16-byte header and the ROMs.
Notebooks
`.IPYNB`	Jupyter notebook	Code, notes and saved results as cells in a JSON document.
Shaders
`.SPV`	SPIR-V shader module	Compiled shaders for Vulkan and OpenGL, as a stream of 32-bit words.
Build files
`.SLN`	Visual Studio solution	The projects and build configurations of a Visual Studio solution, as text.
Packages & installers
`.APK`	Android package	Android apps: a signed ZIP of DEX code, resources and a manifest.
`.DEB`	Debian package	Software for Debian and Ubuntu: an ar archive of control and data tarballs.
`.JAR`	Java archive	Java programs and libraries: class files and a manifest in a ZIP.
`.MSI`	Windows Installer package	Windows install packages: a database of tables inside a compound file.