From L to R: Amazon Web Services, Google AppEngine and Microsoft’s Azure Services offer some of the leading cloud computing platforms.

In the beginning, computers were devices that filled rooms and whole buildings. They slowly shrank in size until, in the 1980′s, computing underwent a revolution, bringing Apple Macs and IBM PC’s to our desks. In the 1990′s, we began to connect all those personal computers to each other using the internet, creating a global network of computers. We are now in the midst of another revolution. The current transformation is again returning computing power back to machines that fill rooms and even entire warehouses, but this time, instead of a single computer filling that space, there are thousands of them filling data centers run by new, old and unexpected companies. These new data centers are being used to create a ‘cloud’ of network-accessible services and have recently been rebranded with the latest buzzword (at Azavea, we always seek to be fully buzzword-compliant) as ‘cloud computing’.

DecisionTree geographic calculation tools running on the Amazon cloud computing services will enable you to run high performance geographic calculators without requiring your own infrastructure.

Cloud computing has actually been around for a while. Even before the internet, networked computers that could break up many tasks into small chunks were said to be engaged in ‘distributed computing‘ or, more recently, ‘grid computing‘. Cloud computing is the same concept applied to internet-connected computers. It really got started several years ago with attempts to engage global networks of PC’s into large-scale science problems. The SETI@home project enabled people to contribute their idle PC’s computing power toward examining radio signals for evidence of extraterrestrial life. Similar projects for insight into protein folding diseases, decryption and the Large Hadron Collider for processing LHC experiments have been joined by global networks of spammers and hackers who manage thousands of compromised computers to form ‘botnets’ that are used to attack government computer systems or blackmail companies.

Aside from those bent on curing cancer or instigating global mayhem, contemporary cloud computing efforts are frequently aimed at more modest objectives. Amazon.com, the retailer, is one of the leaders in this field. What began as a way for Amazon to sell unused capacity in its data centers, Amazon Web Services (AWS) is now an entire suite of reusable services being leveraged for all sorts of activities that have nothing to do with selling books and movies. The AWS Simple Storage Service (S3) is an online data storage service. The AWS Elastic Compute Cloud (EC2) enables software developers to create ‘virtual’ computers running Linux or Windows that can be applied to any computing task. Other AWS services include credit card transactions, message queues, web search, and order fulfillment. AWS has been joined by similar services at Google and a new Microsoft effort called Azure.

Many cloud computing providers provide dashboards displaying system availability.

Now imagine you are a small company that has a new idea that will require lots of computer servers. Before AWS and other services, you would have purchased your own servers and built a data center. Now, you can skip all that hassle by hosting your new idea on an infrastructure maintained at a much lower cost by Amazon, Google or Microsoft. These services are priced like your electricity and gas — you pay by the unit of storage, computing time or other metric. So as you need more capacity, you fire up another virtual server, but you only pay for what you use.

So what does cloud computing mean for geospatial services? Cloud-based geospatial services are already common. The API’s for GoogleMaps, Yahoo!Maps, Microsoft Virtual Earth, and ESRI ArcGIS Online systems already provide some basic map display, geocoding, routing and other geospatial information services as hosted services. While none of these are based on the metered pricing that Amazon offers, I’m confident this type of business model is coming. A new company, Cloudmade, is focused on creating commercial services that leverage the OpenStreetMap database.

At Azavea, our cloud computing work has focused on two of our services: Cicero and DecisionTree. To learn more about Dave Felcan’s research project on the AWS Elastic Compute Cloud (EC2), read his article below.