2. XBlock Overview# 2.1. Introduction to XBlocks 2.1.1. Overview 2.1.2. XBlock API and Runtimes 2.1.3. XBlocks and the edX Platform 2.1.4. XBlocks for Developers 2.2. XBlock Examples 2.2.1. Google Drive and Calendar XBlock 2.2.2. Examples in the XBlock SDK