Polka dot is a framework for building blockchains and getting them out quickly. It comes with automatic upgradeability, which is not something that's generally available in blockchains at all. You basically get most of the technology behind polka dot for free.
We finally sit down with Gavin to go through a bit of what Parity has been working on with Polkadot and Substrate. We talk about Polkadot early history and who was involved and where the idea spawned, up to coding practices and where Substrate became a thing.
If you want to know more, links below.