Types of OSX apps out there

I'm actually starting to feel really guilty about this stupid website, and since I had to write out a quick blurb about the different types of OSX apps that I'm aware of I figured it's as good a way as any to fill up some space.

There are at least 6 very different types of applications running on OSX. IE, OSX is Mach + BSD userspace as a kernel, with varying technologies running "on top of it". Some run within the BSD environment (such as apache) while others barely know BSD is there. Below is some cliffnotes.

(1) BSD-*unix style GUI-less, usually c or c++ applications that run straight within the BSD environment. These are usually fairly trivial to port from linux/freebsd/openbsd/netbsd to OSX, barring having to replace certain functionality such as /random (although I think that was put back in).

(2) Java/Java Cocoa/Swing Apple's gotten really into integrating Java. This means you have .jar's running with a swing interface (cross platform, such as limewire), down to gui-less java apps and even "cocoa" applications written in java instead of objective-c.

(3) Classic Old > OSX applications, which run in the classic compatibility layer, which is basically an instance of OS9 running as a separate process within OSX.

(4) Cocoa Old next/openstep API's, retooled for OSX, although a lot of intermingling has gone on with carbon, to the point where it's hard to make certain types of apps without using Carbon calls, and even then some cocoa calls might actually just be wrappers for carbon calls.

(5) Carbon Old > OSX API's ported to OSX, ripping out 10-20% off the really scary old API's. All of adobe's apps that I'm aware of are Carbon applications, which means they took their old codebase and had to replace sections where appropriate as the API's changed, retool their event model, etc. So for these to "run" within linux you'd have to either port the Carbon API's to linux, or just access them, such as through "mac on linux" which i believe only runs on PPC linux machines.

(6) X11 Apps Older windowing interface for linux applications. Pretty creaky, yet also very very cool in things like it's client server model. A lot of GUI linux apps out there use this, and Apple has even done some really nifty stuff whereby X11 ties into Quartz with an OSX look and feel. Things such as open office and others use this.

Heh, there are even potentially more that are coming (and other subclasses i didnt mention) with the advent of some of the KDE tools coming out.