Ever since the Web moved from being a tool of academia to a platform for commerce and communication, companies have looked for ways to leverage its “access from anywhere” and “zero install” nature for applications.

I’ve written about this before when the industry I then worked in was consumed by the hype over Web-based applications. At the time, there were two chief limitations in moving complex business applications to the Web: One, the user interface technology did not lend itself to eight+ hours of data entry and review. Two, fast, reliable access to the Internet was far from pervasive. Both problems had to be solved if rich applications could live only online.

Flash forward to today and technology exists to solve the first — all of what we call Web 2.0 is built on this idea of providing a rich user experience in a browser. Utility applications like Flickr and social networking sites like Facebook are possible because technology tools exists to create real interactivity. The paradigm is seductive on many levels. One never has to carry a laptop or worry what computer the data is on; software developers don’t have to worry about operating system or installing files.

But problem number two — the existence of gaps in our access to the Internet — remains. If we look at the progression of application platforms from the fat client, local machine era to the network-is-everywhere era as a continuum, there’s a stop in the middle. A hybrid where applications can live in either space and are usable offline as well as online.

This is where Adobe Air comes in. Using the same technologies (Ajax) that powers rich internet applications, Air allows these apps to run offline. The idea is that developers can write the same code and run it as a desktop application and in the browser. Check it out.