lain-psx-decompiled

What you need: Both discs of Serial Experiments Lain (Japan, SLPS-01603 and SLPS-01604) as Redump-format .cue/.bin images, dumped from your own copy.
SHA-1 of a correct dump, by version:
Disc 1: 6426fbdb45f27e089af650cddb8c41929c7890de
Disc 2: 409668af454a0e0a33a71c1d22918d765e718608

lain-psx-decompiled is a decompilation of Serial Experiments Lain whose C source rebuilds the original executable byte for byte, plus a native client for Windows, Linux and macOS. The client runs the same code on a reimplementation of the PlayStation libraries based on PsyCross, with no emulator.

Game logic and timing match the PlayStation. The client adds resolution scaling, fullscreen, optional 60 fps motion smoothing, standard memory-card saves and subtitle and dub packs; the launcher can download the laingame.net English fan subtitles, which are not bundled. A separate tab shows content on the discs that the game never uses.

The whole game is playable, including both sites, all sessions and movies, disc swapping and all four endings. The download contains no game data. It needs both discs of Serial Experiments Lain (Japan), dumped from your own copy.

How to set it up

1. Download the build for your system and extract it.
2. Run lain.exe on Windows, ./lain on Linux or Lain.app on macOS (right-click, Open); the builds are unsigned.
3. In the launcher, add both disc images; the client checks them and copies them into its data folder.
4. Choose the window size and subtitles, then press Play. F1 opens the in-game menu.