GData: The end of Google's walled garden

Google's recent release of the GData protocol has caused some confusion.

It's a matter of interpreting it correctly: GData is not a stand-alone application, it's just a protocol. It is a general framework for posting/editing/deleting XML data to already existing feed.

For example, check out the Google Calendar API. Here it is, in a nutshell: Google has an XML schema that lets you describe events on your calendar. Adding/editing/removing events on your Google calendar is just a matter of using the GData protocol to put/update/delete the XML representation of an event to a feed provided by Google Calendar. GData just handles all the infrastructure stuff, such as authentication, versioning, etc.

Other objects in Google-land have their own XML schema (Google calls these kinds). For example, the Message kind can be used to represent an email, a blog entry, a comment on a blog post, and a posting on a newsgroup. The Contact kind can represent a person, a location, or venue. Using the GData protocol, Google can create APIs that let you interact with each of these kinds.

Now, what does this all mean? In the past, Google has taken a lot of flak for being a walled garden: the data that users put on a Google app, is only accessible thourgh that application (Google Base is the most famous example of this). GData changes the situation completely: it provides a framework for Google to easily and consistently create APIs for all of their applications.

Put simply, GData means that the walled garden of Google's applications is coming to an end. I'm really excited to see what will come out of this.