I've been spending a lot of time and thought into determining what I don't like about OS X. It's easy to tell what I do like: Increased stability, very pretty 'HollywoodOS-esque' graphics, BSD underpinnings, the Dock... It's harder to quantify those things I don't.

First and foremost, I don't like that Apple took moving to a new architecture as an opportunity to make sweeping changes in the user experience. Certainly there are a lot of behaviors that would have to change to accomodate the new framework of the OS, and it's understandable that when Apple had to rewrite the visualization layer (Aqua), they would put in all kinds of improvements like display-postscript, alpha channels, and all the rest. But that didn't mean they have to make the OS a showcase for all those bells and whistles, at the risk of alienating long-time users who have stuck with the mac because of its ease of use and, just as crucial, its consistancy.

Ten years ago, the swtich from System 6 to System 7 was a fundamental change in how people used their Macs. Gone was quitting one application before you could start another. Options like collapsing windows to their title bar or even having a system clock were brought to the system, by taking the most successful shareware utilities and folding them into the OS. In a sense, this is what Apple has done with OS X, and many of the features are 'borrowed' from other utilities or OSes. The dock is clearly an attempt to build a better DragThing (or insert toolbar of choice here) and the traffic light (the green, yellow and red buttons) in the window's corner emulates that of several other desktops, especially KDE and Gnome.

But my biggest problem with the new OS is how it deals with multiple applications. I don't think it's terrible to have small introduced into the OS, though it's questionable to introduce so many, all at once, without the ability to 'settle-in' to them by way of making several optional.

One of the most fundamental paradigms of Mac OS, and the most distinguishing points of diference between the Mac OS and Windows, Linux, Soalris, and the other Unix variants, is that it's application- rather than document-centric. What I mean by this is that, on the cognitive level, you switch from using one application to using another application, rather than from using one document to another. In OS 9 (or 7, or 8), when you want to switch from your photoshop document to your word document, you can do so several different ways, either selecting the proper application from the application menu on the top right, clicking on a document's window to bring it to the front, clicking the application in a third-party dock, or what have you. No matter which way you choose to get there though, your Mac, at that moment 'becomes' Word. the Menu bar is reconfigured for word. Floating toolbars pop into existence to aid you with your word tasks, and all your word documents pop to the front. OS X, on the other hand, treats the application as nigh invisible, centering around the document. As is the case with other document-centric OSes, each document should be seen as having the power of the application as a framework, but not seen as running 'within' the application. Click on a browser window in Windoes, and that window comes forward. Close the last window and the application is gone, not as if it quit, but because it's simply no longer necessary.

I'm not here to say which model is better, though I'm probably showing a leaning toward the application-centric 'modal' model, but it is interesting to note that several Windows applications, including Adobe Photoshop and, even more interestingly, Microsoft Word, Excel, and the rest of hte Office suite, behave as if the document-centric view isn't optimal and create a single window for their documents, a 'virtual desktop' where all the open Word docuements, for example, can live together and share the immense toolbars and palettes the application requires. In this case, they're emulating an application-centered model within a document-centered model for a truly displeasing and inefficient result. Other Windows applications, and Unix apps, hold their functionality entirely within the document's own window. Open an Explorer or Netscape brower and you have menus, toolbars, and the rest all within the single window. when you bring it to the front to use it, you're not fundamentally changing the computer into a 'Navigator', you're just getting a better look at one existing process so you can use it.

Wow I'm getting long-winded. If anyone expresses the need, I'll rewrite this into a more cohesive article but if you've come this far, then it doesn't really matter.

Okay, so we have a 2x2 matrix. The X axis is the 'window metaphor' axis, and it has two options: Document-centric and Application-centric. Document-centric is where an individual docuemnt of an open application can be manipulated, brought forward, sent back, closed, or even quit without having any impact on other open documents of the same application. Application-centric is where the application is seen as a singular entity which may have one or more documents open, but all the documents come forward when you activate one, and quitting the application closes all the documents.

The Y axis represents whether the OS is modal in nature or not. That is to say, whether the fundamental unary interface elements that live outside the document window, such as the menu bar, floating palettes and toolbars, change to reflect the 'currently active' application.

Windows falls into the 'document-centric non-modal' box. Several more complex applications within windows fall into the 'application-centric non-modal' box because all the applications documents are held together in a common 'application window' (the aforementioned Office suite, Photoshop, and many others). This breaks the metaphor and is bad, beacuse it hinders the new user from understanding the consistant computing metaphors used in the OS (because they aren't consistant), and consequently hinders them from getting work done efficiently.

Mac OS 9 (and 7 and 8) is an 'application-centric modal' OS. Click one doc window an they all come to the front. Quit and the docs all close. You can always tell what application 'you're in' by looking at the menubar.

Linux is 'document-centric non-modal' mostly, but some applications have associated toolbars that pop to the front when a document of that application is brought to the front (GIMP is a good example of this behavior).

Mac OS X is a hodgepodge, worse than either Linux or Windows. It's document-centric, in that you can bring one document of an application to the front while leaving the others buried, but it's also application-centric in that you can bring all the documents to the front by clicking on the application's icon in the Dock. It's modal in that the menubar changes to reflect the 'currently active' application, it's so modal, in fact, that it breaks even the document-centric/application-centric dualism going on. Case in point: Open application A, open three documents with application A (Docs 'A1, A2, and A3'). Now open Application B, and open one document with it ('B1'). Right now B1 is in front, and A1-3 are behind. Bring A1 to the front, and you get expected behavior. The menubar shifts to 'App A' mode, and A2 and A3 are still behind B1. In addition to stacking windows, the drop shadows emphasize this ordering. Now, close window A1. what should happen? In a document-centric view, the next window down, B1 should come to the front, and because it's a modal OS, the menubar would then be an 'App B' menubar. what actually happens is doc A3 jumps up from behind B1 and becomes the active document. The rationale is apparently that, although they're breaking the app-centric model enough to make each document an individual instead of a slave to the application mode, it's still preferable to bring the next doc from an app forward, rather than change apps. This is a clear flaw.

Okay, I've rambled enough. Here's where I'd bring in more supporting evidence, wrap it up in a nice conclusion, probably with a brief analysis of which of these were conscious architecture decisions and which were holdovers that just slipped in, and more importantly, how all this fits into a roadmap of how OSes should behave in purely application-centric and document-centric OSes, and a study on whether both models can or should co-exist in the same OS, but then suddenly I've written a book, or at least a proposal for one.

Hopefully I've stirred up some thoughts, and that's enough to make me feel happy about a quick essay I wrote before breakfast and class.

Opinions are always welcome.