BlackBerry 10 can run Android 4.3 apps using the Android Runtime.
The Q20 uses Microsoft ActiveSync (Exchange) or CardDAV/CaldAV via apps. blackberry q20 linux
This is the most popular workflow for the "BlackBerry Q20 Linux" community. You keep Linux on a server (Raspberry Pi, VPS, or your main PC) and use the Q20 as a thin client. BlackBerry 10 can run Android 4