The BTC ecosystem continues to make a strong push: Programmability expansion solutions are emerging one after another.

Recently, the BTC ecosystem has been making rapid progress on the technical front, especially in terms of Programmability expansion solutions. This article will introduce several noteworthy BTC expansion solutions, including Fractal Bitcoin, AVM, OP_NET, BRC100, and programmable runes.

Fractal

Fractal is a scalable framework based on the Bitcoin Core client software virtualization, which improves the overall network performance by recursively creating a tree structure. It is fully compatible with Bitcoin and activates the op_cat operator for more logic.

Fractal was developed by a team from a trading platform and is expected to launch its mainnet in September 2024. In its tokenomics, 50% is generated from mining, 15% is allocated for the ecosystem, 5% is for early investor presale, 20% is distributed to advisors and core contributors, and 10% is used for building partnerships and liquidity.

In terms of architecture design, Fractal encapsulates bitcoin core into a deployable blockchain software package, running multiple instances on the Bitcoin mainnet through recursive anchoring. It has made some modifications to bitcoin core, such as shortening block confirmation time and increasing block size, to enhance performance.

Fractal has activated the op_cat operator, providing more possibilities for the BTC scaling solution. Different instance chains can communicate, achieving seamless asset transfers. Bitcoin and other assets can enter the Fractal network through decentralized bridging.

In order to enhance security, Fractal has introduced a joint mining mechanism, where some blocks are generated through merged mining with BTC miners. The newly created instance chain will have a protection mechanism in the early stages until it reaches a secure and healthy state.

AVM

AVM(Atomicals Virtual Machine) is the BTC smart contract implementation of the Atomicals Protocol. It creates a virtual machine that simulates BTC scripts, opening up multiple raw BTC opcodes, allowing developers to implement smart contracts through Bitcoin script combinations and define asset management rules.

AVM maximally leverages the original opcode capabilities of BTC, achieving Turing completeness through a dual-stack PDA. It operates in a sandbox that includes an indexer, instruction parser, and global state, enabling smart contract processing and state synchronization verification.

The AVM instruction set includes the complete set of BTC opcodes, allowing developers to program using BTC's unused features. It is an architecture that can be applied to any metadata protocol with just minor adjustments to the indexer. The AVM has released a beta version, and the related code has been open-sourced.

OP_NET

OP_NET aims to introduce smart contract functionality similar to Ethereum, but more aligned with Bitcoin characteristics. Users can trade on OP_NET using only native Bitcoin, without the need for other tokens.

OP_NET provides a complete and compact development library, primarily written in AssemblyScript. It retains the Bitcoin block consensus and data availability, executing complex computations on Bitcoin blocks through the virtual machine OP_VM.

OP_NET supports multiple programming languages and utilizes Tapscript to achieve advanced smart contract functionalities. The smart contract code will be compressed and written into BTC transactions, generating a UTXO address that serves as the contract address.

Users need to pay additional fees when interacting with OP_NET, and the transaction packaging order will be sorted according to the fees. OP_NET also offers a Proof of Authority system, allowing BTC to be wrapped as WBTC.

The OP_NET ecosystem covers multiple areas including decentralized trading, lending, market making, liquidity provision, and cross-chain bridges, with several projects already launched.

BRC100

BRC-100 is a decentralized computing protocol built on the Ordinals theory. It adds new operations such as "burn" and "mint" to brc20, recording the token balances and statuses of different addresses in the indexer, enabling complex defi operations.

BRC-100 provides operations such as mint2/mint3 and burn2/burn3, allowing tokens to be converted between the UTXO model and the state machine model. It supports enhancing computing capabilities and state transitions through extended protocols, all of which are compatible with each other.

The BRC-100 protocol stack includes the BRC-101( on-chain governance protocol), the BRC-102( automated liquidity protocol), and the BRC-104( liquidity staking/re-staking pool protocol), among others. Currently, multiple projects have been launched in the BRC-100 ecosystem, including exchanges, lending protocols, and more.

Programmability Runes ( Protorunes )

Programmable Runes are an extension layer of Runes that allow for the creation of programmable assets with Runes. The Proto-Runes Protocol is the main project in this area, providing a framework for Programmable Runes and supporting the implementation of a Uniswap-like DEX on the Bitcoin network.

The key mechanisms of Proto-Runes include Protoburn(, which converts runes into a form usable by sub-protocols), and Protomessage(, which contains operational instructions within the sub-protocol). The indexer processes these protocol messages sequentially to achieve functions such as asset management and transfer.

Recently, the first Protorune has completed Protoburn, demonstrating the correct operation of the ord indexer. The development team is working on a WASM indexer for this genesis Protorune, aiming to achieve on-chain governance functionality on Bitcoin L1.

These expansion solutions inject stronger smart contract functionality and decentralized application support into the BTC ecosystem, promising to propel the further development of the BTC ecosystem.