One of Android's biggest draws is its roots in open source. It
enables a broad range of device manufacturers to work from the same code
base, and provides app developers with more insight into the platform
they're building on. But openness isn't a binary condition — there are
many shades of gray. While Android is technically very open, from a
practical standpoint it's much more difficult for device makers to distance themselves from Google,
if that's their preference. 'Phone manufacturers and carriers that want
to use Google's services must conform to Google's device standards, a
stricter requirement than what basic AOSP requires. For some, this is a
catch. For others, it's merely the cost of doing business. ... [Dianne
Hackborn, one of Android's tech leads,] defends Google's right to
include proprietary services, and to keep them proprietary, saying that
its no different than any other proprietary app on Android. That's not
entirely true, since Google does keep some API development to itself,
but to its credit the company does open-source most of the new APIs
introduced to Android.