This is a decompilation of Serial Experiments Lain (PlayStation, Pioneer LDC, 1998) and a native client for Windows, macOS and Linux built from it.

The decompilation recreates the game's source code in C. Compiled with the original PsyQ toolchain, it rebuilds an executable byte-identical to the retail one. The native client runs the same code on a reimplementation of the PlayStation SDK, with no emulator.

Disc	Serial	Executable	SHA-1 of the data track (Redump)
Disc 1	SLPS-01603	SLPS_016.03	6426fbdb45f27e089af650cddb8c41929c7890de
Disc 2	SLPS-01604	SLPS_016.04	409668af454a0e0a33a71c1d22918d765e718608

The rebuilt SLPS_016.03 has SHA-1 a0012634f82dd7fcc4ee5a3f97ddc052573b4815. Disc 2's executable is identical.

Important

This repository and its releases contain no game data. Movies, voices, images, sounds, text and data tables are read from your own dump of the two original discs.

Playing

1. Dump both discs in Redump format (.cue + .bin).

2. Download the client for your system from Releases:

   System	Package	First launch
   Windows 10/11 (x64)	Lain-windows.zip	Run lain.exe. On a SmartScreen warning: More info, Run anyway.
   macOS (Apple Silicon)	Lain-macos.zip	Right-click Lain.app, Open.
   Linux (x86-64, glibc 2.35+)	Lain-linux-x86_64.tar.gz	Run ./lain. Needs OpenGL 3.2.

   The builds are not signed.

3. In the launcher, add both discs (file picker or drag and drop). The client verifies them and copies them into its data folder.

4. Choose window size, subtitles and options, then press Play.

F1 opens the in-game menu: display, volume, languages, key bindings, cheats and mods.

PlayStation	Keyboard	In Lain
D-pad	Arrow keys	Move the cursor, select a node
○	V	Confirm, open a node
×	C	Back
△	Z	Menu (load, save, ...)
Start	Return	Continue, skip

Gamepads work as controller 1. Full controls and options: port/PORTING.md.

Features

Feature	Details
Original behaviour	Game logic, timing and pacing match the PlayStation, measured on real hardware.
Display	Resolution scaling, fullscreen, optional 60 fps motion interpolation at the original game speed.
Subtitles and dubs	Plain .srt, .ass and .ogg folder packs. The launcher can download the laingame.net English fan subtitles from their source; none are bundled.
Saves	Standard 128 KiB memory card images (.mcd), usable with emulators.
Unused content	A launcher tab showing content on the discs that the game never uses, decoded from your own dump. See docs/findings.
Mods	Replace pictures, text, voices, movies and game data, HD texture packs, Lua scripts that hook any game function, and native plugins, managed in the launcher's Mods tab. See MODDING.md.

Status

Part	State
Decompilation (src/)	All 321 game functions are C that compiles to the original bytes, and the EXE is byte-identical. Sony's PsyQ libraries link from their original code.
Native client (port/)	Plays the whole game: both sites, all voice sessions and movies, disc swap, all four endings.
Naming	Most functions, globals and struct fields are named.

Open work is tracked in docs/ROADMAP.md.

Building the client

Requirements: CMake, a C/C++ compiler, SDL2 and OpenAL (openal-soft).

# macOS:  brew install cmake ninja sdl2 openal-soft
# Linux:  apt install cmake ninja-build libsdl2-dev libopenal-dev libgl-dev
cmake -S port -B build/port -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build/port
build/port/lain

The Windows build is cross-compiled with MinGW-w64 in Docker, from macOS or Linux (port/tools/package_windows.sh below).

Release packages link every dependency statically:

port/tools/package_macos.sh     # dist/Lain-macos.zip
port/tools/package_windows.sh   # dist/Lain-windows.zip (MinGW-w64 in Docker)
port/tools/package_linux.sh     # dist/Lain-linux-x86_64.tar.gz (Ubuntu 22.04 in Docker)

Building the decompilation

Requirements: Python 3, Docker (provides GCC 2.8.1-psx and maspsx), and both disc dumps.

python3 -m venv .venv && . .venv/bin/activate
pip install -r requirements.txt
tools/disc.py extract path/to/disc1.cue --disc 1
tools/disc.py extract path/to/disc2.cue --disc 2
tools/docker.sh make split   # disassemble the executable into asm/
tools/docker.sh make         # compile, link and verify

A successful build ends with build/SLPS_016.03: OK. To work on functions, see docs/MATCHING.md.

Repository layout

Path	Contents
src/	Decompiled game code (matching)
include/, config/	Headers, splat configuration, symbol maps
tools/	Disc extraction, build and matching tools
port/game/	64-bit copy of the game code used by the client
port/psx/	PlayStation SDK reimplementation, based on PsyCross
port/client/	Launcher, overlay, settings, subtitle and dub packs, mods
docs/	Technical documentation and findings

Documentation

Document	Topic
DECOMPILATION.md	How the decompilation is organised
MATCHING.md	Matching workflow and tools
PORTING.md	Client internals, pack formats, options
MODDING.md	Making and using mods
findings	Unused and hidden content
ROADMAP.md	Open work

License

The code in this repository is released under the MIT License, copyright Y0oshi. Third-party components keep their own licenses; see thirdparty/.

Serial Experiments Lain is the property of its respective rights holders. This project is not affiliated with or endorsed by them. The icon is adapted from the game's memory card icon.