Lightweight Programming Models

Once the idea of web services became au courant, large companies jumped into the fray with a complex web services stack designed to create highly reliable programming environments for distributed applications.

But much as the web succeeded precisely because it overthrew much of hypertext theory, substituting a simple pragmatism for ideal design, RSS has become perhaps the single most widely deployed web service because of its simplicity, while the complex corporate web services stacks have yet to achieve wide deployment.

Similarly, Amazon.com's web services are provided in two forms: one adhering to the formalisms of the SOAP (Simple Object Access Protocol) web services stack, the other simply providing XML data over HTTP, in a lightweight approach sometimes referred to as REST (Representational State Transfer). While high value B2B connections (like those between Amazon and retail partners like ToysRUs) use the SOAP stack, Amazon reports that 95% of the usage is of the lightweight REST service.

This same quest for simplicity can be seen in other "organic" web services. Google's recent release of Google Maps is a case in point. Google Maps' simple AJAX (Javascript and XML) interface was quickly decrypted by hackers, who then proceeded to remix the data into new services.

Mapping-related web services had been available for some time from GIS vendors such as ESRI as well as from MapQuest and Microsoft MapPoint. But Google Maps set the world on fire because of its simplicity. While experimenting with any of the formal vendor-supported web services required a formal contract between the parties, the way Google Maps was implemented left the data for the taking, and hackers soon found ways to creatively re-use that data.

There are several significant lessons here:

Support lightweight programming models that allow for loosely coupled systems. The complexity of the corporate-sponsored web services stack is designed to enable tight coupling. While this is necessary in many cases, many of the most interesting applications can indeed remain loosely coupled, and even fragile. The Web 2.0 mindset is very different from the traditional IT mindset!
Think syndication, not coordination. Simple web services, like RSS and REST-based web services, are about syndicating data outwards, not controlling what happens when it gets to the other end of the connection. This idea is fundamental to the internet itself, a reflection of what is known as the end-to-end principle.
Design for "hackability" and remixability. Systems like the original web, RSS, and AJAX all have this in common: the barriers to re-use are extremely low. Much of the useful software is actually open source, but even when it isn't, there is little in the way of intellectual property protection. The web browser's "View Source" option made it possible for any user to copy any other user's web page; RSS was designed to empower the user to view the content he or she wants, when it's wanted, not at the behest of the information provider; the most successful web services are those that have been easiest to take in new directions unimagined by their creators. The phrase "some rights reserved," which was popularized by the Creative Commons to contrast with the more typical "all rights reserved," is a useful guidepost.