What is Adobe AIR? Adobe AIR(Adobe Integrated Runtime) is a fantastic new technology that greatly expands the ways in which you can create desktop applications.
Traditionally, programs like Microsoft Word, the Firefox Web Browser, and Adobe Reader have been written in a programming language like C or C++.
Learning such technologies, while not hard, takes some effort, and making graphical applications, let alone cross-platform apps, using them in an even larger hurdle.
Now, with Adobe AIR you can use whatever Web development know-how you have be it Adobe Flash, Adobe Flex or standard Ajax(HTML and Javascript) - to create fully functional desktop applications that will run equally well on Windows, Mac OSX and Linux.
Why should I use Adobe AIR? The first and most compelling reason is that using Adobe AIR is easy.
In all likelihood you'll just apply the knowledge you already have.
In the worst case scenario, if you have limited to no experience with HTML and Javascript, rest assured that few technologies are as approachable as these.
The learning curve for using Adobe AIR is therefore short but the upside is huge.
A second but very strong reason to use Adobe AIR is that it automatically generates cross-platform applications.
The programs you create will equally well on Windows, Mac OS X, and Linux regardless of the operating system on which they were written.
Adobe AIR was designed specifically with this in mind, and there are but few areas in which operating system-specific steps need to be taken.
A third consideration to note is that with Adobe AIR you're creating graphical applications: programs that are visible, that run outside of any consule window or terminal application, and that can take full advantage of the user's mouse and keyword.
This may not sound revelatory to you, but when using other technologies (like C or C++) to make an application, creating a graphical application as opposed to a command-line utility isn't that simple.