Its a smart contract platform, written in C#, that is based in China. It claims some features that Ethereum doesn't have such as parallel contract execution, smart contract authoring in C#, and instead of general mining, they have an Accountant node which is elected by participants of the network and validates all transactions (similar-ish to DPOS).

Their documentation says that one feature of the Account node is that you can pay them off chain to get your contracts mined for free.

I plan on building and testing NEO this weekend, but it does concern me that the blockchain is developed in China and 'elects' nodes that have full control over the network. It strongly implies that China will make them elect govt. controlled nodes to be accountants, but that could just be me being paranoid.

Their github is here (and not very active): https://github.com/neo-project

I chose not to invest after looking at their code, especially at the quality of their compiler, which is very messy code without any test cases, but I can't help but play around with it in a private network.

just consider the name/handle 'crypto' that should tell you were its heading 5 milliamps of hexadecimal bullshit that is wrapped in numerical magic called algorithms try exchanging it for real food/water or anything among 6 billion humans who have no idea what you are talking about so as long as you live in your internet substitue vacuum reality enjoy your dellusions but don't ask for help/food/water etc when the power goes out! dumb people do dumb things believing in their own ignorance ..

It's a Chinese Ethereum, as best I can tell.