Stacks is a Bitcoin L2, bringing smart contract functionality to Bitcoin, without modifying Bitcoin itself. Stacks takes a pyramid approach, where you have the foundational settlement layer at the bottom (Bitcoin), and then a layer on top of that to add smart contracts and programmability (Stacks), and then layers on top of that for scalability and speed (Hiro's Subnets).

Alpen is a scaling Bitcoin with Zero Knowledge technology solution. The platform build infrastructure to enable the broader, adoption of Bitcoin. Ushering a new era of trustless, verifiable computation.

Solv is a Decentralized Bitcoin Staking Protocol to unlock the full potential of Bitcoin assets through a liquidity consensus infrastructure. By addressing the fragmentation of BTC assets, yield opportunities, and custody solutions, Solv offers Bitcoin holders a gateway to BTCFi, continuously builds pathways and confidence for traditional funds to enter the crypto world.

Merlin Chain is a Bitcoin Layer 2 powered by Bitmap, building upon the native assets, protocols, and products on Bitcoin Layer 1, to Make Bitcoin Fun Again.

Launched on Bitcoin mainnet by developer Casey Rodarmor on January 20, 2023, Ordinal NFTs are simply the latest way to create NFTs on Bitcoin. Ordinals are means of creating Bitcoin NFTs by attaching data such as images, videos, and more to an individual satoshi on the base Bitcoin blockchain. Unlike their predecessors, ordinal NFTs don’t exist on a separate layer from Bitcoin. Rather, they use an arbitrary but logical ordering system called ordinal theory to give each individual Bitcoin satoshi a unique number. In this regard, ordinal NFTs are completely Bitcoin-native. They work without changes to the Bitcoin protocol, don’t require any extra layers, and are backward compatible with the network.

Lorenzo Protocol is an on-chain asset management platform that tokenizes and integrates CeFi financial products into DeFi, aiming to connect on-chain capital with a wide range of off-chain financial strategies. With tradable tickers, users can easily engage in complex yield strategies. As yield infrastructure, Lorenzo powers financial access products such as Neobanks, Payment Finance, Wallets, PayFi, RWAFi, DeFAI, and more, enabling the large-scale integration of sustainable on-chain real yields.

Bitroot is a Layer 2 scaling solution for Bitcoin as the programmable asset issuance protocol enables issuance of fungible Tokens and NFTs on the Bitcoin Chain and with the implementation of OP_CAT and BitrootVM it enhances the capabilities of smart contracts, making possible that users and developers can create and manage their own digital assets on Bitcoin's infrastructure keeping the high decentralization and security, enabling broader asset representation, expansion and operability.

bitSmiley is a Bitcoin-native Defi project that has innovated in both application design and protocol layers. Its groundbreaking Fintegra framework comprises three main components: a decentralized overcollateralized stablecoin protocol, a native trustless lending protocol, and the on-chain derivatives protocol. bitSmiley will initially introduce bitUSD, a native overcollateralized stablecoin on the Bitcoin blockchain, addressing the lack of stable price-pegging tools. Users can generate bitUSD by overcollateralizing their BTC, allowing participation in all BTC blockchain DeFi protocols. Each bitUSD is backed by overcollateralized BTC, ensuring stability and user asset security through a robust liquidation and repayment system.

Mintlayer is a blockchain platform designed to expand Bitcoin's functionality. By enabling atomic swaps with native bitcoin for use in DeFi, powering real world asset tokenization and incorporating innovative consensus mechanisms, Mintlayer aims to revolutionize the DeFi landscape.

Bitlight Labs develops infrastructure based on the RGB protocol and deploy multiple applications on LightningNetwork, with a primary focus on implementing the trading infrastructure for RGB20 tokens.

BTC Domain is a bitcoin domain name service platform where users can register a name and associate it with their bitcoin address. BTC Domain provides an experience similar to the Ethereum Name Service (ENS) by providing a wide range of name-related services, including name registration, name resolution, and other related services.".btc" domains are inscribed as formatted JSON text onto the Bitcoin mainnet, with each domain being a unique inscription that is akin to a BTC NFT.

ODOS is an Ordinals OS that offer assets management and Inscription trading Bot service.

Interlay is building its flagship product, "InterBTC," a fully collateralized one-to-one Bitcoin-backed asset that enables interoperability between multiple blockchain ecosystems while preserving Bitcoin's censorship-resistant nature. Interlay v2 proposes introducing native DeFi functionality to the network: a decentralized AMM-based exchange (Uniswap v2 model and Curve Stableswap) paired with a liquidity protocol for BTC borrowing and lending (Compound v2 model). By creating markets catering to Bitcoin holders and building deep liquidity in these protocols, Interlay will enable easy, one-click access to Bitcoin-centered DeFi use cases, ranging from simple passive liquidity provision to tailored long/short leverage positions.

Function is a crypto infrastructure company that issues FBTC, which allows institutions and corporate treasuries to efficiently deploy Bitcoin while maintaining full custodial control over their cryptocurrencies.

Sats Terminal is a Bitcoin-native aggregation protocol, offering seamless access to aggregated swaps and liquidity across multiple Bitcoin DEXes and DeFi platforms.

Luminex is a Bitcoin Ordinals launchpad platform, that allow users to participate fairly in the Bitcoin ecosystem.Luminex has proposed the BRC-69 standard, designed to simplify the creation of Recursive Ordinals collections, reducing inscription costs and streamlining the on-chain pre-reveal process.

TREX20 is revolutionizing and pioneering in GameFi built on Bitcoin Protocol with Multiple Games and NFTFi Marketplace and progressive lotto under one roof.

Mirror L2 is a decentralized Proof of Stake (POS) BTC L2 compatible with EVM and smart contract while utilizing BTC as GAS. POS nodes utilize mBTC, the mirrored version of BTC on the L2, as collateral proof for the L2.

Ordiswap brings dynamic AMM infrastructure to BRC-20, unlocking liquidity on Bitcoin's native layer. At its core, Ordiswap seamlessly integrates off-chain server management with the unique tokenization capabilities of the BRC-20 standard.

BitRGB is a Bitcoin asset management platform based on the RGB protocol, supporting the issuance and trading of Bitcoin assets such as NFTs and tokens.The protocol leverages the paradigm of client-side validation, keeping all transaction data related to BitRGB off-chain and using the Bitcoin blockchain solely as a commitment layer to prevent double spending.

BiHelix is a Bitcoin ecological infrastructure based on the Bitcoin native blockchain, combining the RGB protocol and the Lightning Network to build optimized nodes. It aims to make it easier for developers to use, increase the use cases of Bitcoin, and solve the challenges of scalability and Turing incompleteness faced by the Bitcoin blockchain. Create a fairer decentralized encryption world for miners, validators, node service providers, exchanges, and users.

Bison is a cutting-edge rollup amplifying transaction speeds, while enabling advanced functionalities on native Bitcoin. Developers can craft innovative DeFi solutions like trading platforms, lending services, and automated market makers.

The goal of AIPTP is to build a decentralized blockchain-based AI network. AIPTP decided to build a dual L2 network for Bitcoin. Where: Bitcoin L2 (tentatively AIS) with POS mechanism supports AIPTP's training model; Bitcoin L2 (tentatively AIW) with PoW mechanism supports AIPTP's inference model. $Bitcoin & $ATMT can cross-chain circulation between the three chains, where $ATMT adopts the burn+mint cross-chain circulation method, and $Bitcoin adopts the pledge A chain and release it in B chain for cross-chain swap.

Bnzk Labs aims to integrate Zero-Knowledge (ZK) Proof technology into the Bitcoin ecosystem in a BTC Native Manner. Bnzk uses ZK-proofs to address decentralization and verifiability issues of existing Bitcoin protocols such as ordinals.Bnzk solves this problem by validating ordinals transactions off-chain and generating on-chain ZK-proof.

BadgerDAO is focused on building the products and infrastructure needed to accelerate the growth of Bitcoin in Decentralized Finance (DeFi) across multiple blockchains. Badger's first product, Sett Vaults, enables users to earn yield on their synthetic BTC assets. Digg, Badger's second product, is software that manages the DIGG token, a cryptocurrency with an elastic supply pegged to the dollar price of Bitcoin.

BNSx is a Bitcoin Name Service System that offer Identity Verification SDKs and Secondary Domain Service. The BNSX project aims to revolutionize decentralized identity solutions on Bitcoin's Layer 2 networks.

Rollux is the EVM rollup platform base on Bitcoin’s PoW for security, scalability, and affordability. Rollux is developed by SYS Labs, and functions as Syscoin’s Layer 2. Rollux will initially be an Optimistic Rollup, and will incorporate ZK-based rollups once Validity-proving technologies mature.

Yuzo | BRC2.0 is an AI-powered Bitcoin Ordinals Launchpad that allows users to create, publish, and trade Ordinals.

Sandshrew is a remote procedure call (RPC) service customized for developers seeking full access to Bitcoin and Ordinal blockchain data.

XRGB Labs aiming to revolutionize digital assets by integrating Bitcoin into Layer 2 solutions for enhanced scalability, speed, and cost-efficiency. XRGB Launchpad and XRGB Swap together form a comprehensive ecosystem that nurtures creativity and facilitates seamless digital asset exchange on the RGB network.