What is Ethereum ???

How would I explain Ethereum to a non-technical friend?

I've recently attempted to explain Ethereum to several non-techy friends.

My explanation usually involves starting with a comparison to Bitcoin, but this quickly becomes complicated as I then have to explain the backstory of how the Bitcoin blockchain works, which is similarly technical in nature.

Ethereum is a world computer [1] and might change how we interact, just like the internet did, 20 years ago. Like Bitcoin, it is based on a block chain, but Ethereum is more than just a currency:

Transparent governance for communities
Secure communications - authentication, messaging,
Secure backbone for e-commerce and the Internet of Things
Secure payments
Integrated development environment for debugging, development and deployment of Ethereum applications
Free software - all released under the General Public Licence (GPL)

Is there a better way to describe the general concepts of Ethereum to non-techies? Are there any analogies I can make to things that are less technical in nature? Or is it just the case that the technology is quite complicated...?