Matrix World is a decentralized open virtual world that enables users to interact with 3D immersive applications while simultaneously running on different blockchains. The world is made up of Lands, which are issued as Non-Fungible Tokens (NFTs) and permanently persisted on blockchain networks such as Ethereum and Flow. Thus, the Matrix Lands are tradable and transferable via blockchain networks, and their owners retain complete control over the creations on their Lands. More technically, Lands can be bounded to a sandbox in Matrix Network, and the sandbox has its own compute and storage resources. These resources allow the landowner and creators to govern the visual appearance, inner properties, and lifecycle logic of the Land's creations, ultimately resulting in the production of a 3D immersive application that can operate in perpetuity in the Matrix cyberspace. In Matrix World, users can take advantage of traditional 3D open-world features such as building 3D architectures, hosting virtual meetings, exhibiting digital assets (e.g., NFTs), and more advanced functionality such as creating and hosting their own 3D decentralized applications (DApps) using Matrix's built-in creator services and computational resources. These DApps include 3D games and 3D marketplaces, among others. Our ultimate goal is to create unlimited possibilities and opportunities for metaverse by eliminating the boundary between multiple blockchains and building a next-generation 3D open-world DApp platform on top of Matrix World.