The BTC ecosystem expansion plan is thriving, with multiple programmability solutions emerging.

Since the first quarter of 2024, the technical aspects of the BTC ecosystem have progressed rapidly, especially in the area 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 virtualized based on the bitcoin core client software, which improves the overall network performance by recursively creating tree structures. It is fully compatible with Bitcoin and its infrastructure, activating the op_cat operator to enable more logic.

Fractal is developed by the Unisat team 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 pre-sale to early investors, 20% is distributed to advisors and core contributors, and 10% is used for establishing partnerships and liquidity.

Fractal encapsulates the bitcoin core client into a deployable blockchain software package (BCSP) using virtualization technology, and recursively anchors multiple BCSP instances running on the Bitcoin mainnet. It makes some modifications to the bitcoin core, such as shortening the block confirmation time to 30 seconds and increasing the block size to 20MB.

In terms of security, Fractal introduces a joint mining mechanism where one out of every three blocks is generated through merged mining with BTC miners. The newly created virtualized instance chain will experience an initial vulnerability period during the startup phase, and operators can set specific block heights to provide protection.

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 BTC opcodes, allowing developers to implement smart contracts through the combination of Bitcoin scripts.

AVM achieves Turing completeness through a dual-stack PDA, running in a sandbox that includes an indexer, instruction parser, and global state. Its instruction set contains the complete BTC opcodes, allowing developers to program using BTC functionalities that are not yet enabled on the mainnet.

AVM is an architecture that can be applied to any metadata protocol, requiring only minor adjustments to the indexer under the virtual machine. A test version has been released.

OP_NET

OP_NET is committed to introducing Ethereum-like smart contract capabilities on the Bitcoin network. It provides a complete, compact, and user-friendly development library, primarily written in AssemblyScript.

OP_NET retains the block consensus and data availability of Bitcoin by executing the virtual machine (OP_VM) to perform complex computations on Bitcoin blocks. It supports multiple programming languages and utilizes Tapscript to enable advanced smart contract functionalities.

When interacting on the OP_NET network, users need to pay additional transaction fees. To expand the use of BTC in DeFi applications, OP_NET provides a Proof of Authority system that allows BTC to be wrapped as WBTC.

The OP_NET ecosystem encompasses various fields such as decentralized trading, lending, market making, liquidity provision, and cross-chain bridges, including projects like Motoswap, Stash, and Ordinal Novus.

BRC100

BRC-100 is a decentralized computing protocol built on the Ordinals theory, which expands the brc20 functionality through new operations to achieve complex defi operations. It provides operations such as mint2/mint3 and burn2/burn3, allowing tokens to be converted between the UTXO model and the state machine model.

The BRC-100 protocol stack includes multiple extension protocols, such as the BRC-101( decentralized on-chain governance protocol ), the BRC-102( automated liquidity protocol ), and the BRC-104( liquidity staking/re-staking pool protocol ).

The BRC-100 ecosystem includes multiple projects, including inBRC( the first BRC-100 market and indexer ), 100Swap( based on the BRC-102 protocol AMM DEX), and 100Layer( liquidity protocol on Bitcoin L1 ).

Programmability Runes ( Protorunes )

Programmable Runes are an extension layer of Runes that allow the creation of programmable assets with Runes. The Proto-Runes Protocol is the main project among them, providing the framework for programmable Runes.

The core mechanism of the Proto-Runes Protocol includes Protoburn( which converts runes into a representation usable by sub-protocols) and Protomessage( operation instructions in the sub-protocol). It represents protocol fields and messages using LEB128 encoding, with each sub-protocol having a unique protocol label.

Recently, the first Protorune - QUORUM•GENESIS•PROTORUNE has successfully completed the Protoburn. This genesis Protorune is intended to serve as a public forum for Protorune standards and can provide governance functions for project tokens.