As a big milestone in the development of NEO3, NEO has launched the NEO3 TestNet and released NEO3 Preview1 today.

With the launch of NEO3 Preview1, NEO has taken a tangible step forward in terms of advancing NEO3 while enabling its developer communities to begin testing and exploring NEO3 upgrades. 

NEO is an open source project driven by the community. It utilizes blockchain technology and digital identities to digitize and automate the management of assets using smart contracts. Using a distributed network, it aims to create a "Smart Economy" by building infrastructures of the Next Generation Internet and creating a solid foundation for mass blockchain adoption.

To accelerate enterprise-grade blockchain innovations for the future, NEO3 will empower developers by completely revamp NEO2 to deliver a scalable platform with higher throughput, enhanced stability and security, an optimized smart contract system, and a feature-packed infrastructure set.

Major features and improvements included in NEO3 Preview1:

• Architecture Optimization
• NEO is moving away from UTXO (Unspent Transaction Output) to an Account based transaction model in NEO3. All assets will be created in smart contracts in NEO3, to fully utilize smart contract functionalities.
• Smart Contract enhancements
• Native contracts for NEO, GAS, and Network Policy that can be invoked by other contracts.
• Auto-claimable GAS
• Contracts will now require application manifest and ScriptHeader to describe its properties, including:
• Application Binary Interface (ABI)
• Contact method descriptor and permissions
• New smart contract APIs: access to notifications and JSON serialization.
• NeoVM is now decoupled from the NEO blockchain and can be used independently.
• Transaction optimizations
• Single transaction type for all blockchain transactions
• Scoped witness (scope for signature usage)
• Transaction outcome is now being stored
• Transaction validation by block height 
• Blocks optimizations
• Introduced maximum size limit for blocks
• Introduced maximum size limit for witness for better spam attack preventions.

• Stability enhancements
• dBFT2.0
• 1/3 fault tolerance
• One-block finality
• Recovery mechanism

• Pricing model adjustment
• Overall fee structure adjusted to greatly reduce system fees, contract deployment costs and NeoVM instruction costs.
• Network fees will be applicable for all transactions.

• Performance enhancements
• Auto compression mechanism on p2p network.

For full technical details, please refer to “A Deep Dive into NEO3 Preview1 Features”

NEO3 Preview1 is now available for download here. While this preview build is subject to changes, NEO urges community developers to use this build as an opportunity to offer feedback.