In the very early days of humanity, primitive cave dwellers were forced to use software installed directly on their office computers. They would have to run from cave to cave (often in bad weather, possibly dodging wild animals like the giant sloth) in order to install “updates” whenever the software was improved, to make sure each cave was doing consistent, compatible work. Sometime after the invention of the wheel and the Enlightenment, a few cave men came up with the Internet. I’m glossing over lots of important things. Eventually, people realized that the Internet would be a great way to deliver software-like services without having to maintain individual caves.

Today, many of us use a number of web-based applications. Here’s a list of what I’ve used so far today:

• Backpack - a lightweight personal information manager (PIM)
• Google Reader - alerting, monitoring
• Gmail - email
• Heroku - an integrated development environment (IDE) [ed: technically, working with this after midnight counts as “today”]
• Flickr - photo sharing
• Oracle - finance-y stuff
• A Number of “News Services” - blogs, most of which were application-calibre
• My GXS Blog - publishing and feedback
• Trading Grid Online - of course

However, we still use desktop software. Some of our software handles large local files and work wells on the desktop–think Photoshop. Serious 3D games are very performance and latency-sensitive and also handle local texture files and model files. One of the newest questions being tackled by development groups like Microsoft, Adobe and Mozilla goes something like this:

“Is there a middle ground between a pure web application and a pure desktop application? A web application delivered on the desktop, with desktop integration. How would this be accomplished? What would the benefits be?”

This is a really interesting line of thought.  Imagine signing on to your work computer one morning and finding a desktop icon called Trading Grid Online.  When launched, you would be using the Trading Grid web portal, but as if it were a locally-installed program.  It would show up in the taskbar.  You could alt-tab around with your other programs.  You could drop files in to the web-based transaction manager directly from your file browser.  In fact, the program would minimize to your system tray and show a desktop pop-over window each time a transaction alert triggered on the Trading Grid.   Now, imagine that a new version of the portal was released.  Because your desktop version simply packages the on-demand web service, no local upgrade would be required.  The benefit of both worlds?  Sounds good to me.

There are a number of competing approaches and technologies starting to explore this space:

• Adobe AIR - I have not researched AIR extensively on the developer end, but have used an AIR-based application call.  The AIR approach is to use technologies like HTML w/ Javascript or Flash/Flex (Adobe technologies) to build desktop applications with access to local files and remote data.
• Microsoft Silverlight - This project, while often lumped in this list, appears to be about creating rich internet applications (RIAs) based on the Microsoft .NET platform.  That makes it a competitor to some of the Adobe technologies used by AIR.  I have yet to understand how Silverlight intends to push the melding of the desktop and the full on-demand web application.
• Mozilla Prism - This system is based on the idea of providing a dedicated “Firefox” desktop window for a web application, removing things like the location bar, bookmarks, etc. to create the single desktop app feeling.  I believe web developers could use custom tags in their pages to invoke things like desktop alerts through the Prism framework.  I’ve played with this a bit and its clearly very early stage.  Mozilla’s approach seems to be based on enhancing integration via packaging and extending an existing web app, but not custom-writing one.
• Google Gears - I want to try Gears in my evening time to see how it works, but the idea is not so much to provide a brand new type of application as it is to provide a code library for web applications that are on the web (in the normal sense) to support an “offline” mode by storing data on the user’s desktop and referencing from the web.  This is one kind of integration with the desktop, but doesn’t cast as wide a net as AIR or Prism.

Exciting times for the Internet.  There is some convergence brewing even if none of these particular technologies become the next wave.  Google Docs as an “office suite” is growing in popularity, but mostly for niche web-sharing uses.  Microsoft Office, OpenOffice and Apple iWork all still excel in usability when dealing with local documents; any given user will have tons of these lying around the cave.  One of the major, unsettled questions that you can see lurking in the list is still the question of how the web and desktop will come together.