While there were some reports floating around that parts of Android might not be as open source as original thought, Google has come out and made it clear: the core Android platform will be 100% open source.

ZDNet confirmed with various Google employees that everything will be open r. Besides a couple exceptions, everything will use the Apache software license (ASLv2). There are two exceptions, which according to ZDNet are:

1. Software that is already covered by by a free/open source license will continue to use that license. Most notably, this includes Google’s enhancements to the Linux kernel. Linux uses the GNU Public License (GPL v2) so enhancements to the kernel will use the same license.
2. Any software that touches Eclipse, for example the Eclipse Android Development Tools plug-in (ADT) will be licensed under the Eclipse Public License (EPL), because that’s what Eclipse uses.

The core Android system will be open source, but there’s no guarantee that carrier,s OEMs and application developers will keep their applications open source. Google is encouraging it, but does not mandate it, which means that some application developers may choose to keep their source code closed or have limited access.