Well, it's a good thing it's not a *nix app then. :-)
Actually, I was thinking about this sort of thing the other morning. The old idea of one app for one task seems to largely be abandoned in modern graphical applications.
Then I got to thinking about Firefox and it's bevy of extensions, some of which are basically full fledged applications strapped onto a browser. That's when I started thinking "what if gecko was an extension?" Or rather, what if Friefox was nothing more than a basic framework for sticking extensions into.
Then you'd be back to the old *nix style of application development, except where before it was one task == one application, it would become 1 task == 1 extension. Then, instead of creating "applications" by chaining commands with pipes, you would create applications by assembling a series of extensions.
A desktop environment using this model would still have applications like you know, them, but they'd actually be more like bookmarks. The web browser link wouldn't start Firefox, it'd start your HTML Renderer/_javascript_ Engine/Bookmark Manager assembly.
In this mythical computing environment, the extensions would click together as easily as you can pipe grep output through sed. The assemblies would just be for convenience (much like the shell scripts of old) and you could knock an assembly together for a simple one off application.
Actually, as I sit here typing this, I'm starting to realise that web apps are starting to do something like this. That's exactly what this is:
http://en.wikipedia.org/wiki/Mashup_%28web_application_hybrid%29
Bringing the conversation back towards Google Wave, given their open api and the ability to embed extensions (at the moment it's only robots and gadgets, but I'm hoping more stuff will go in), I'm betting we're going to start seeing more of exactly this sort of thing.
With Chrome OS coming soon, maybe that was the plan all along...
