Credit where it is due - Google has changed its mind about dropping an open standard and has added one to its list of publicly accessible APIs.
Back in March Google announced that CalDAV, an open standard for accessing calendar data on the web, was being withdrawn from public view. It would only be available to Google's partners.
This effective closure was another sin chalked up against Google and there was a lot of complaining - and quite rightly so. Now Google has announced that it has listened to requests to keep CalDAV public and added CardDAV, an open standard for accessing contact information, to its publicly available APIs.
Sadly, it does emphasize how little upbeat news there has been about Google's services recently, but let us not complain when something good has happened.
In addition to making the two APIs available there are some updates. Both CalDAV and CardDAV are integrated with the Google API Console and they both make use of OAuth 2.0 for authentication. CalDAV has a courtesy limit of one million requests per day and CardDAV has a limit of 10,000 requests per day - both very reasonable.
The APIs are both RESTful APIs and to use them all you have to do is sign up to Google and stay within the courtesy limits. The revised CalDAV API has a new end point. The old one, and the ability to use HTTP Basic Authentication, will be closed on September 16,2013. This will make existing apps stop working unless they are upgraded.
See - Google can be good.
Now about Reader, XMPP ...