Blocks and Geometric are both enormously complicated projects; doing a proper job of open sourcing them would take a lot of engineering time and effort. They would also be almost impossible to support and maintain as core reference resources. Blocks is also built on an early alpha version of our interaction engine that we're still preparing for release.
We're focused on building and sharing lots of smaller projects that developers can use as building blocks, rather than one or two massive projects that would basically require people to reverse-engineer them.