In the recent TechWise blog PaaS & the cloud Continuum we discussed the structure and phenomenon of Cloud computing.  There really are two technological evolutions occurring simultaneously.  One is the movement of storage and services to the cloud and the other is the push to interconnect these services.  This shift to increased interconnectivity forms the basis of Web 2.0

If you browse the blogsphere for Web 2.0 articles you will often see terms like Service Oriented Architecure, API's, Web Services and WSDL's.  These all refer to methods and technologies that allow Cloud based applications to interact with the user via the internet as well as communicate with each other.  To help understand this it is valuable to put some focus on the technology of how internet interconnectivity works.  The primary way that information is communicated over the internet is Hyper Text Transfer Protocol (HTTP).  There are other methods for applications to communicate with each other, such as direct database communications or FTP but the vast majority of internet communication is via HTTP

What has blossomed over time is the use of HTTP to extend simple communications with a specific website or domain to include communication across domains.  For example, we often write functions to extend QuickBase application functionality by calling scripts on our MCF Web Services domain.  Those scripts can then execute functions onQuickBase or call functions from other domains such as UPS, Google, Docusign, etc.  These connections can be real-time, button click operations or asynchronous, performed behind the scenes using scripts or an integration engine likeTalend ETL.

One of the challenges of Web 2.0 Interconnectivity is the standardization of security and communication models.  In effect there are three styles of cross domain communication.  The first is a very simple URL string model which incorporates parameters that in the URL that are read by the target site.  google does this quite well.  For example the following URL string will conveniently locate the MCF offices on a Google Map: http://maps.google.com/maps?q=2509+professor+ave+cleveland.  The more advanced models for communication still use HTTP but utilize a multi-part submission that contains the URL, an HTTP header and a message body.  Of this style there are two basic types of communication interfaces, Representational State Transfer (REST) and (Simple Object Access Protocol) SOAP.

In a recent blog discussion with Gartner's Neil MacDonald there is some good dialogue around the security benefits and usability of these styles of web interconnectivity.  In truth both have benefits and drawbacks that are nuanced and overly technical for this article.  The important takeaway is the understanding that these methods of cross domain internet communication are the foundation of the current technology evolution, which is defined by the move to Cloud computing and Web 2.0 intereconnectivity.  When selecting Cloud technologies, especially SaaS and PaaS it is critically important to consider the ability to support communication to and from the application via well established methods such as REST or SOAP interfaces.