The application does tons of vector drawing…. it draws hundreds of thousands, even millions, of line segments. Yet it needed to be responsive… scrolling, zooming, panning. It’s data intensive, too. It downloads dozens of megabytes of data for each view. I needed to develop this program fast, so I needed a programming system and platform allowing me to iterate and adapt to new requirements recursively revealed. […] So here’s the spoiler: I chose Java Web Start + JRuby. And now a short dissertation on how I arrived at that choice.