This is a response that I posted in the a thread about Adobe Apollo and Joyent Slingshot. It answers the question “Why do these offline web platforms matter?”
The fact is that people still use desktop applications, and those applications by-and-large offer better integration and responsiveness than their online equivalents.
If anything, this is a direct assault on the entrenched desktop programming world. These platforms blur the line between thin and thick desktops, they enable a single standard for cross-platform development, and they open new frontiers for web-based developers. That is no small achievement!
Removing the browser’s chrome is a big step. Others have already moved in this direction, notably Konfabulator. Konfabulator takes brilliant advantage of this web-based, cross-platform environment through Javascript, XML , and its own self-contained runtimes. Adobe, Slingshot, et. al. are opening up that environment to a larger audience.
Think of it another way: could you develop a desktop application for Windows, Mac, and Linux, with all the bells and whistles, as quickly as you can build a *single* online app? No? Well, now you can.
A Canvas for Thought 