- NEM is built 100% from scratch (not a fork of any existing project)
- NEM is built with test-driven development.
- NEM uses innovative Proof-of-Importance algorithm: first reputation based blockchain algorithm.
- NEM is the first crypto with delegated harvesting.
- NEM improves different features of POW and POS coins, being more efficient and environmentally friendly.
- NEM has customizable assets called Mosaics. Editable supply, levies, description, transferability and more.
- NEM has Namespaces to help maintain reputation of Mosaics.
- NEM one minute average block times.
- NEM has advanced blockchain features: multilevel multisig (Multisig 2.0), aggregate transactions, account properties, cross-chain swap.
- NEM is the first with localized spam protection.
- NEM is the first with Eigentrust++ peer reputation management.
- NEM is the first editable m-of-n multisig with blockchain based alerts.
- NEM is the first every P2P network with nodes time syncing in a decentralized manner.
- NEM offers encrypted, unencrypted and hex messaging.
- NEM is easy to install with a one-click installer.
- NEM zero monetary inflation (fixed supply, all 9 billion coins released at launch).
- NEM relatively large egalitarian distribution.
- NEM will offer mobile wallets for both iOS and Android.

Consensus Mechanism: Proof-of-Importance
Genesis Date: March 31st, 2015
Block Time: 1 minute
Available/Total Supply: 8,999,999,999 XEM
Block Reward: N/A (transaction fees only + node rewards)

XEM
XEM is the native currency of the NEM public blockchain. It is used to pay for transactions on this public blockchain in order to incentivize its network of public nodes that process and record transactions for businesses and users there. This means that XEM has real fundamental value as the currency of a functioning economy.

Harvesting
Harvesting is closely similar to mining in other cryptocurrencies, but it uses unique methods called Proof of Importance and Delegated Harvesting to determine who harvests the next block. Harvesting is necessary to keep the network online and to confirm transactions.

Supernode Program
Supernodes are high performance blockchain nodes which form the backbone of the NEM blockchain network. Accounts with 3,000,000 or more XEM can operate a supernode, either from a local computer or from a cloud-hosted server. Supernodes are required to be up and running 24 hours per day, processing all transactions.

Catapult
Catapult is a full-featured blockchain engine that can power both private and public networks with its unique smart contract plugins. These plugins enable bulletproof digital asset creation, decentralized swaps, advanced account systems and business logic modeling.
In its next phase, Catapult will become the core NEM engine. Public chain Catapult has been in testing for three years to thoroughly troubleshoot bugs and implement features. Its expected release is in 2019.

Proof-Of-Importance
POI is the consensus algorithm used in NEM to determine who will calculate the next block. An account's importance is determined by how many coins it contains and the number of transactions made to and from that account. POI is different from other initiatives which use a fee-sharing model that does not take into consideration one's overall support of the network. In some proof-of-stake systems a person only needs to have large amounts of coins to form a block; however, in NEM the transaction amount as well as support of the network become a factor. This has been designed to encourage users of NEM to not simply hold NEM but instead actively carry out transactions within the NEM ecosystem.

You can read more about NEM’s tech in the Technical Reference.