When Google introduced the Google data APIs two years ago, it did not exactly rock the firmament like, say, other Google offerings.
GData hit the news this month when Google ported YouTube's APIs to the format and released those APIs to the world by putting them with the rest of the GData portfolio. A range of Google applications now use GData, including Google Base, Google Code Search, and Picasa. In addition third parties such as Spanning Sync, BloghHUD and Gumiyo have also adopted GData for their applications.
It's the third-party developers that should worry, though. GData is not a clear standard, unlike some of its component technologies, and GData evangelist Frank Mantek has warned that Google is under no obligation to leave GData unchanged.
In other words, mashups using GData could break if, and when, Google makes changes to the APIs. "There is no commercial contract with Google so there is no protection for any one who uses it," Mantek said at last week's QCon in London.
Such is the price, apparently, of relying on the internet's biggest search and ads company when it comes to using de-facto web standards in the name of simplicity.
Google introduced GData because, according to Mantek, Google had too many APIs for it to succeed in its claimed mission "to organize the world's information and make it universally accessible and useful."
Mantek said Google wanted to create a "universal API" for the web: "There were many different APIs at Google - it was too complicated and a significant problem for us."
Mantek said Google was prepared to gamble and chose to address the issue by basing GData on a combination of still emerging techniques and standards. First, it opted for an approach based on Representational State Transfer principles rather than the more established SOAP.
"We felt that REST was better because it was how the web works and easy to explain. Also developers like it because every API behaves the same," Mantek explained.
Then, there was the decision to use the, then, still emerging Atom Publishing Protocol as a major element of GData, which was something of a surprise.
But the gamble appears to have paid off. Mantek said that, while APP needed some extensions to fulfill GData's requirements, it proved to be a good choice.
"Atom was originally designed for things like blogging, not arbitrary data sets, so we needed to extend it. We had to invent our own query mechanism by introducing a query parameter, and missing authentication was also a problem - but we solved this with Google authentication. Overall, it's been a good decision - especially now our competitors have gone for it," Mantek said.
By competitors, Mantek means his former employer Microsoft which, in a surprising about turn last month, announced it was focusing its efforts on APP. Last year Microsoft criticized GData and said it would base its efforts on a new protocol - Web3S. But it now appears to have quietly abandoned Web3S in favor of supporting APP.®