Which parts of Google Android platform are not open-source?

Question

Which parts of Google Android platform are not open-source?

Answer 1

Pretty much everything is open source. The source is available at https://android.googlesource.com/

The Google apps are generally thought of to be part of the Android platform by consumers, but are not actually. They are not open source.

These apps include, GMAIL Youtube Google Maps Marketplace Maybe a few others I'm missing...

Manufacturer specific modifications such as Motorola Blur and Samsung Touchwiz are not open source.

Maybe hardware specific drivers are not open source.