If you're researching Google's various APIs, you're bound to come across something called the "Google Data API" aka GData. It describes itself as:
The Google data APIs ("GData" for short) provide a simple standard protocol for reading and writing data on the web. GData combines common XML-based syndication formats (Atom and RSS) with a feed-publishing system based on the Atom publishing protocol, plus some extensions for handling queries.
It's a lot more than a protocol though. It also defines a data model ("kinds") for populating commonly used elements. Here's some of the types:
- gd:comments
- gd:contactSection
- gd:email
- gd:entryLink
- gd:feedLink
- gd:geoPt
- gd:im
- gd:originalEvent
- gd:phoneNumber
- gd:postalAddress
- gd:rating
- gd:recurrence
- gd:recurrenceException
- gd:reminder
- gd:when
- gd:where
- gd:who
These elements have deep structure, attributes and other such things. What does it have to do with the Google Base model? Easy to answer: nothing. This is very very unfortunate and it probably a good sign as any that Google's becoming a pretty big company, like IBM or Microsoft.
What use does Google have for GData? It's main purpose at this time is to allow outside to tools to populate Google Calendar. We can only hope this will somehow be merged or made consistent with the Google Base model and API.