I don't need to give a preamble on the interest around cloud computing -- it's here now and organizations are using it in many different ways. ESRI is working with Amazon and offering ArcGIS Server solutions in the cloud. More specifically, there will be Amazon Machine Images (AMIs) with ArcGIS Server pre-installed and configured and ready to run. Details around licensing and support are coming at the 2010 ESRI International User Conference.
What about Geocortex Essentials in the cloud? Essentials REST Elements requires no special software other than a supported operating system. This is a recipe for success for pairing Essentials REST Elements with one of the many Amazon EC2 Windows offerings. To prove this, I fired up a basic Windows EC2 instance running IIS, made sure that port 80 was open, downloaded and installed Essentials REST Elements with all default settings, and everything was up and running as expected. I realize that EC2 is giving me basically a regular instance of Windows and so this isn't totally surprising -- but I found it pretty cool nonetheless given that it took me about 15 minutes.
So, bottom line is that Essentials REST Elements is more than happy to run on Amazon's EC2 cloud offering. Keep in mind that this is a preliminary result, and is not saying we official support Amazon EC2. At least not just yet -- we'll keep this testing going and give an official green light soon.