I thought it'd be cool to see if processing.js, the Javascript version of the graphics library Processing, could work in Node.js, the serverside Javascript engine. Thanks to the existing canvas module that I didn't write, it didn't take too long to get something working. Obviously it doesn't do animation but you can render a frame then save the canvas output to a file.

I had to make a few changes to the processing source, as it tries to register all sorts of touch events on elements and though I was able to implement a number of dummy interfaces to handle them (see index.js in the processing module) I couldn't do them all. Also, I've never made a module before so it's probably not packaged up properly.

Anyway, if you do node app.js then that will read the contents of sketch.pde and output the final PNG.

Various methods will fail, like trying to load an image, or pretty much anything other than drawing shapes. It would probably take a bit of a rewrite of Processing.js to make it work properly outside of a browser. You can probably do all the stuff you want accessing the canvas module natively, really.

The canvas module uses Cairo, so on Windows or Mac it probably won't work straight away unless you install that.