About Retrario

Retrario is a research project that puts PlayStation 2 classics in the browser, to play with friends: open a tab, send a link, kick off together.

How it is built

The emulator. Retrario is built on Play!, the open-source PlayStation 2 emulator by Jean-Philip Desjardins and its contributors. Without it there would be no Retrario. The project's fork compiles Play! to WebAssembly with threads and adds what a browser needs: the game read from the browser's own storage, compiled code kept between sessions, and the lockstep that lets two browsers play one match.

The page. The app around the game is written in React: the hub, the settings, the lobby, the friends and the game requests.

The server. A small Node server sends the page and the game's files, keeps the accounts and the friends lists, and runs the lobby that brings two players together. The match itself goes directly between the two browsers.

What the project measures

The goal is a steady 50 frames a second with no lag, offline and online, with bounded memory and processor use, on an ordinary computer. Every change to the emulator is measured before and after on the same game scenes, and ships only when the numbers hold.

Players' sessions report their frame times too. They are grouped by class of computer, and the game card in the app tells you whether computers like yours hold a steady 50 fps, are not steady yet, or are not measured yet. The classes are on the requirements page.

Where it is going

PlayStation 2 comes first. The hub already shows the consoles planned after it (PlayStation 1, SNES, Nintendo 64, Game Boy Advance), and the players' votes in Request a game decide which game comes next. A new game gets its own page only when it is playable.

Contact

For questions, bug reports or someone to play with, use the community link in the app (the Community screen). The FAQ answers the common questions.

Rights

Game names and marks belong to their owners; Retrario is a research project and is not a place to get game files.

Play now Chrome or Edge on a computer, nothing to install.