Case 1: the application is not an executable. It is a bundled package. There are significant differences. Meanwhile, it can run from anywhere. I run applications from my Downloads folder. And Spotlight still recognizes it as an application. The Applications folder is merely a convenience.

Case 2 does not require you to drag the file. If you run an installer package it automatically adds the program to the right folder.

Case 3: DMG files auto-mount when Safari downloads them (and they should for other browsers, too). This lets developers add a shortcut to the Application folder.

The Mac version of Open Office demonstrates the worst of all cases.

OpenOffice is a terrible program. It's bad on Windows, it's bad on Ubuntu.

That said: there's some terminology you need to know. A DMG is a disk image. That should be simple. It's a virtual disk. An application is an app. An installer is an installer. Apple doesn't bullshit you. Unlike Windows, they don't refer to something by vague, nebulous terms. They tell you EXACTLY what something does.

So when I boot the DMG, it contains an application. That app IS the app. It tells me to drag the app to the applications folder, as a courtesy. I don't have to. I can move the app to my root folder, or to my Movies folder, or I can mount the disk image every time. That's like putting a CD in to run a program, only virtual. That's a logical spatial metaphor unless you deliberately misread everything.

Now, Apple had a problem, which is: "How do we help people organize their apps?" They allowed for multiple solutions to this. The first is the installer, which is overkill. (Windows overuses this because they think usability isn't worth their time. As a result, users install crap on their computer.) The second is that an application can, with permission, move itself. The third is that they let developers modify the Finder window. That means you can write instructions telling people to move an application to the App folder, which you saw.

Isn't that great?! No password. Nothing special. They just gave you a disk that shows you both the application and the folder it ought to be in, and they let you drag it. It's brilliant!

Exactly what problem(s) does this dmg file address and why is it not needed in Windows?

Amichail, I don't know you, so forgive me if this is impertinent, but you don't seem to have a clue about how Macs work. You don't seem to have put any research into the ideas behind OS X. You also exhibit an irrational pro-Windows bias.

I used Windows for seventeen years. In that time, I suffered no small amount of horrors thanks to the fucked-up system that is the executable file. Files that auto-execute slow up my computer. They run without asking and copy themselves all over my system. They release viruses. They encourage sloppy coding habits. Don't you dare suggest that Windows' system doesn't require thinking. Get an 80-year-old, direct them to the download page for, say, Google Toolbar, which has a GOOD installer, and say nothing. See if they figure out how to download the executable, run it, and get it working. Internet Explorer has a fix by asking you immediately to run an EXE, but that leads to lots of nasty things getting executed by accident.

The Mac system is beautiful in its simplicity. I'll go so far as to accuse you of deliberately misunderstanding things to paint an anti-Mac situation, which is pretty irrational on my part, because I have such a love for the system, which works like this:

* You have a dock entry for Downloads for things you download. This bounces when you get a new downloaded item.

* Click that stack and it opens up so you can click the newest thing.

* If it's an app, it runs. It doesn't mess things up like an EXE because an app can't write to certain parts of your computer than an EXE can. That means that even if you launch an app, it can't do much to screw up your computer.

* The Applications folder is not magic. It just has a label for you to dump things. You don't ever need to use it. That said, the fact that there IS an Applications folder beats the pants off of Program Files.

* Some programs need more access to system files. They have an installer, which gives you more information about the application and asks you to enter a password.

* Programs that need more than a single package use a disk-mounted image, which is LIKE the shitty fucking programs that use shitty fucking zip to bundle a ReadMe on Windows. The difference is that on Mac, this fulfills a very useful work metaphor. Think of it like inserting a CD into your computer, only virtually. Just as your computer mounts the CD, so too does it mount the disk containing your various files.

Applications aren't DMGs. Applications are applications. The problem is that WINDOWS is fucked up. They let executables be both installers and actual programs, and their file handling is so appalling that people are never certain just where a program is. Is it that original exe? Is it somewhere in Program Files, which is a veritable wasteland? People get used to it after a decade of learning this twisted, bizarre, sad system, but that doesn't make it any less fucked.

So if I put in a CD and there's an application, and it gives me a big window with a shortcut to the Applications folder with an arrow saying "Drag this to this folder," and I do so, and then I eject the CD, wouldn't I be pretty damned stupid to assume that the application was broken? (Well, maybe in Windows, where it's still good work habits to make programs that require CDs to run, but in the rest of the world?)

DMGs don't add clutter. They're a Finder window. If I close it, they stay plugged in, because Apple's idea is that a window and an application should not be one and the same. Same goes for DMGs. If I close a CD's browser window in Windows, does that eject the CD? No. That would be very stupid.

Either you're very, very deluded thanks to overuse of Windows, or you're deliberately casting the Mac in a bad light, which I find despicable. I'm sorry for ranting - it's rude and possibly offensive to you - but at the same time, I simply can't imagine how you could find something wrong here unless you were going out of your way. You seem to have a thing for Windows 7, and I have sympathy for you, but in your last post and in this one you're going out of your way to disparage a very good system that makes things simple, and your defense is ignoring the fact that the Windows alternative to the Mac system is exactly why Windows is as bad as it is. You could have attacked the many failings of OS X, but you instead insulted something that it does better than Windows in every way.