Designed to let you easily deliver Gmail-enabled features, this new API is a standard Google API, which gives RESTful access to a user’s mailbox under OAuth 2.0 authorization. It supports CRUD operations on true Gmail datatypes such as messages, threads, labels and drafts.
As a standard Google API, you make simple HTTPS calls and get your responses in JSON, XML or Google Protobuf formats. You can also make these calls from standard web languages like Java and Python without using a TCP socket, which means the API is accessible from many cloud environments that couldn’t support IMAP.
I wonder what this means for Apple’s Mail applications.
While I think open standards like IMAP should be used when at all possible, Google has a history of home-built APIs over open standards when it gives them more control and allows developers to build more powerful applications. Just ask CalDAV or XMPP.