What's this?
A Minecraft Classic client written in JavaScript, utilising WebSocket (Classic speaks TCP, so a WebSocket-TCP bridge is needed) with Typed Arrays for communication and map parsing, three.js for 3D graphics, and zlib.js for map decompression.
How do I use it?
Start up a local web server pointed at /src. I like using PHP 5.4's built-in webserver:
$ cd src
$ php -S localhost:8000
Next, you'll need to run a Minecraft server. I'm using the official Minecraft Classic server which is long-outdated and can't even send heartbeats these days, but it's a good compatibility test. It is started like so:
$ java -Xms512M -Xmx512M -cp minecraft-server.jar com.mojang.minecraft.server.MinecraftServer
Make sure you disable heartbeats and name protection in server.properties:
public=false
verify-names=false
Finally, we use a WebSocket-to-TCP bridge. I'm using the, quite frankly, rubbish ws-tcp-bridge which has a habit of crashing whenever it loses connection. Still, good enough for local testing. It can used like this to proxy localhost WebSocket traffic on port 25566 (currently the hard-wired server in the client) from the TCP Minecraft Classic server port 25565:
$ ws-tcp-bridge --lport 25566 --rhost localhost:25565 --method ws2tcp
OK, but is it worth using?
Maybe not just now. It runs at decent FPS, but may freeze your browser for a while when preparing the map. You can move around in it, but it ignores most packets (it doesn't even display players). But hey, we're getting there! You can even chat with T!
Why is it called manic.js?!
It's a reference to Manic Digger, an open-source Minecraft Classic clone, of course. Since Notch objected, the Classic-compatible mode was disabled by default, but it's easy to re-enable by compiling Manic Digger yourself. (Shhh, don't tell Notch!)