NEM—short for New Economy Movement—is one of the earlier public blockchains to take a payments-and-assets approach with built-in features rather than external smart contracts. The original public chain, often called NIS1, has been running since 2015, and in March 2021 the project’s next-generation chain, Symbol (XYM), launched as a separate network after years of development (codename “Catapult”).
This article gives you a concise, educational tour: where NEM came from, how its technology works (especially Proof-of-Importance and harvesting), the system’s early “smart-asset” ideas—mosaics, namespaces, multisig, Apostille—and how they set the stage for Symbol.
The one-minute overview
- NIS1 (the original NEM chain) went live in 2015 and introduced Proof-of-Importance (PoI) plus a user-friendly, built-in toolkit for assets and accounts.
- PoI picks block producers by a score that reflects both stake and on-chain economic activity, not just wealth. Blocks are “harvested,” not mined.
- NEM popularized smart-asset primitives: namespaces (DNS-like names), mosaics (configurable tokens), and multisignature accounts at the protocol level, plus Apostille notarization.
- In 2021 the team launched Symbol (XYM), a separate public chain using Proof-of-Stake+ (PoS+), aggregate transactions, and other upgrades. An opt-in airdrop granted XYM to XEM holders at launch. NIS1 continues to operate alongside Symbol.
A short timeline
- 2015: Community-built NIS1 starts production; the chain has continued running since.
- 2016–2017: Documentation and evangelism around smart-asset features mature; the Apostille notarization standard is published (Jan 2017).
- 2016–2020: “Catapult” (later Symbol) is developed as the next-gen engine with enterprise-friendly features.
- March 2021: Symbol mainnet launches; XYM distributed one-to-one to eligible XEM holders via an opt-in and snapshot process.
NEM’s big ideas (NIS1): PoI, harvesting, and smart-asset tooling
Proof-of-Importance (PoI) & “harvesting”
Most people know Proof-of-Work and Proof-of-Stake. NEM tried something different: Proof-of-Importance. In PoI, your chance to create the next block depends not only on stake but also on how actively your account participates in the economy (who you transact with, and how often). That activity is weighted to discourage gaming while rewarding useful behavior. Blocks are produced through harvesting, NEM’s term for block creation under PoI.
Two details learners often ask about:
- Vesting threshold: To harvest, an account must have 10,000 XEM vested—coins that have aged in the account long enough to count toward importance (each day ~10% of unvested XEM becomes vested).
- Delegated harvesting: You can “lease” your importance to a remote account and harvest from another machine (or a provider) without risking your main keys—NEM calls this importance transfer.
This design encouraged ordinary users to help secure the network while keeping costs low for light clients.
Namespaces & mosaics (NEM’s “smart assets”)
Before today’s token standards became common, NEM offered a built-in, DNS-style naming system (namespaces) and mosaics, configurable on-chain assets you can issue under your namespace (for example, mybrand.coin or city.tickets). Namespaces establish unique roots; mosaics inherit that uniqueness and configurable properties (supply, divisibility, transfer rules).
Multisignature accounts (protocol-level)
NEM integrated m-of-n multisig directly into accounts. Converting a regular account to a multisig account assigns cosigners and sets how many signatures are required for any spend or configuration change. Because multisig is native, experiences like rotating signers or building shared treasuries are straightforward.
Apostille (blockchain notarization)
The Apostille system combined namespaces, mosaics, messages, and multisig to create a versioned, transferable notarization workflow on-chain. Rather than a one-time hash proof, Apostille lets you brand, register, and update document attestations over time—useful for legal documents, IP, and certifications.
Supernode rewards program
Because NEM did not rely on ongoing inflation to pay miners, the project earmarked a pool of XEM to reward high-performance supernodes that meet reliability and throughput benchmarks—boosting data availability for light clients and apps.
From NEM to Symbol: what changed in 2021?
The original chain (NIS1) is still online, but the project’s forward-leaning features live on Symbol (XYM), launched March 2021. The handover worked via an opt-in airdrop: eligible XEM holders at snapshot received XYM on Symbol at a 1:1 ratio. (Late claimants had a post-launch retrieval window.)
What Symbol brought:
- Proof-of-Stake+ (PoS+) consensus: Symbol retains NEM’s “activity-aware” spirit by modifying PoS to factor in behavior that supports the network, not just stake size.
- Aggregate transactions: Multiple actions from several parties can be bundled atomically—either all succeed or none do—enabling trustless swaps, escrow, and complex flows without bespoke smart contracts.
- Richer transaction set & metadata: Symbol adds first-class transaction types and metadata you can attach to assets (e.g., legal names, identifiers) while keeping large documents off-chain.
For learners comparing networks, think of NIS1 as the original PoI-based chain with pioneering smart-asset features, and Symbol as the modern, modular successor with PoS+, aggregate txs, and a broader enterprise toolkit. Both exist today; they serve different goals.
What is XEM used for on NIS1?
- Fees & spam resistance: Tiny fees are burned on each transaction.
- Security participation: Vested XEM enables harvesting; delegated harvesting lets you do this from a remote node safely.
- Asset operations: Creating or managing namespaces and mosaics uses XEM-denominated fees.
Why NEM still matters in crypto history
Even if today’s developer momentum is stronger on Symbol, NEM introduced patterns now familiar across chains:
- Activity-aware block production (PoI): It pushed the conversation beyond “rich get richer” staking.
- Smart-asset UX before Turing-complete scripting: Namespaces, mosaics, and native multisig delivered practical asset and account controls years before many token standards matured elsewhere.
- On-chain notarization workflows (Apostille): Not just proof-of-existence, but lifecycle management of notarized records.
Those ideas informed the design of Symbol, which formalized PoS+ and aggregate transactions to enable more complex, atomic business logic.
Closing thoughts
If you’re studying blockchain history and design, NEM (XEM) is a worthwhile stop. It championed Proof-of-Importance, made multisig and asset issuance first-class citizens, and experimented early with document notarization. Those primitives—plus lessons learned—fed into Symbol (XYM) in 2021, which continues the lineage with PoS+ and aggregate transactions for more complex, atomic workflows. Whether you’re comparing consensus models, learning how early smart-asset systems worked, or tracing the path from NIS1 to Symbol, NEM’s story is a compact primer in practical blockchain engineering.