I explained tech and ideas behind NEM, might be helpful for newcomers

NEM NEM is a blockchain for managing assets and papers. NEM employs Proof-of-Importance (PoI) as a consensus algorithm. To be able to produce (or harvest) blocks, a user should have at least 10000 coins. Each node has the importance score. The higher this score, the more probable for the node to be able to harvest a block. The Proof-of-Importance is close to the Proof-of-Stake algorithm. The main difference is that PoI also considers whether the node participates in transactions with the rest of the network. A user can lease his harvesting power. This allows to get a chance of creating a block and thus receiving a reward to those who don’t want or can’t actively harvest blocks. NEM has built-in multisig support. Usual accounts can be converted into multisig accounts. These accounts can add or remove cosignatories. To make a transaction, a majority of cosignatories should sign it. NEM has a spam protection. When the number of new transactions is small, all transactions are going to the blockchain. When this number is big, the priority is given to the addresses with high importance and high fees. An attacker could not just create a lot of addresses, as they will have low importance. The only way for an attacker to spam the blockchain in to pay high fees. To protect from malicious nodes, NEM uses reputation system. Initially, the new node connects to the set of trustful nodes defined by a user. They all have the same trust level. After that, as trustful nodes share the information about other nodes, the trust level is calculated as the ratio of successful interactions divided by the total number of interactions. Finally, it aggregates trust values from local nodes. The reputation system helps to connect to trustful nodes and to balance the load of the network. NEM introduces Supernodes, the concept similar to Masternodes in Dash and a two-tier network in Waves. Supernodes are full nodes that are meant to secure the network. To become a Supernode, a node should stake big amount of coins and meet a set of criteria on hardware performance. NEM offers rewards to the Supernode owners from the Supernode’s fund. NEM expands the possibilities of the blockchain. It introduces the concepts of addresses, mosaics, and namespaces. Addresses, or smart assets, are containers for the mosaics. An address can represent a personal wallet or company assets. Mosaics are fixed pieces of information that can work with each other. Mosaic can be tokens, coins, votes, or signatures. Namespace is the alias, or folder, to organize a variety of addresses and mosaics into a manageable system. Catapult is the project based on NEM architecture. Its goal is to bring a simple and efficient solution to the banking industry. The software used in financial sectors is old and slow. Moreover, it costs a lot to replace it and to adopt new standards. Catapult offers a simple and organic solution, which can be scaled if proven effective. Catapult is made by Tech Bureau. Apostille is a notarization and timestamping service based on NEM blockchain. It is an advancement of the first-generation projects on the blockchain. Those projects could only put file hash into blockchain. In Apostille, a user can choose between traditional public notarization and private, transferable, and updatable notarization. In the second case, Apostille creates an account for the document, signed by the private key. Timeline June 16, 2014: Release on Bitcointalk. bitcointalk.org April 19, 2015: First commit on Github. github.com September 8, 2015: Release of version 0.6.42. The update brought editable multisig accounts. blog.nem.io January 13, 2016: Launch of Supernodes program. blog.nem.io June 1, 2016: First payment to the Supernode owners. blog.nem.io November 1, 2016: Release of Nanowallet, light NEM wallet. Nanowallet offers advanced features, such as delegated harvesting and Apostille. blog.nem.io January 27, 2017: Announcement of the NEO Foundation blog.nem.io