Demoseen is a developer who builds WebGL and JavaScript demos, cellular automata playgrounds, and tricks like packing code into PNG files.
Commenters enjoy playing with his Langton's ant playground, share their favorite patterns, and describe his PNG packing as an efficient way to ship web demos.
I first learned about this technique from Cody Brocious' post (http://daeken.com/superpacking-js-demos) about his WebGL demo 'Magister' (http://demoseen.com/windowpane/magister.html). That file has a .html extension, but it's also a valid PNG. In his post, he discusses this technique as well as others.
Cody's goal was to compress already minified WebGL code and achieve some pretty impressive results from a ridiculously small file for a demo contest. He also put the JS loader (which is much smaller than the linked decoder) in a custom chunk on the PNG itself. By doing it that way, you can have a PNG that when renamed also contains a web page and/or more Javascript.
It's an interesting technique, for sure, but I've never been able to find a real use for it beyond the compression. With a content-type sniffing vulnerability or something, it could be an interesting way to deliver content to browsers, but otherwise it's really just a curiosity as best I can tell.
hmm it breaks on Chrome on mac os:
System.Exception: TypeError: Cannot read property 'viewport' of null
at ctor.Resize (http://demoseen.com/bridge/WebArena.js:180:37)
at new ctor (http://demoseen.com/bridge/WebArena.js:158:22)
at Function.Main (http://demoseen.com/bridge/WebArena.js:119:13)
at http://demoseen.com/bridge/bridge.js:2973:39
at HTMLDocument.delayfn (http://demoseen.com/bridge/bridge.js:481:21)
at HTMLDocument.listenHandler (http://demoseen.com/bridge/bridge.js:498:30)
I abused this concept to compress demo code in PNG files, with great success. http://demoseen.com/blog/2011-08-31_Superpacking_JS_Demos.html
This is, at present, the most efficient way to pack demos on the web; a few characters of uncompressed bootstrap code, then the rest is deflated.
This is awesome. I'd love to add color generation options.
Here's my favorite so far:
http://demoseen.com/langton.html#*/*/*/*/*/*/*/*/*/*/....
[EDIT: and its cousin: http://demoseen.com/langton.html#*/*/*/*/*/*/*/*/*/*/....+-+-+-+-+-+-+-+-+-+- ]
You mean like this?
http://demoseen.com/windowpane/magister.png.html
(I'm not the creator, I just happen to share an IRC channel with them.) There is a description of how it works at http://daeken.com/superpacking-js-demos
I like the demo on the "front page", as well: http://demoseen.com/
It crashes though, when you run it with this hash: 0FP$9jj!i1!!!DPD!t!!!!!~ It spun up 5M threads before it died, which was admittedly fun to watch.