Matrix World is a decentralized open virtual world that lets users interact with immersive 3D applications simultaneously running on different blockchains. The world consists of Lands, issued as Non-Fungible Tokens (NFTs), which permanently persist on blockchain networks such as Ethereum and Flow. Thus, Matrix Lands are tradable and transferable via blockchain networks and their owners retain complete control over the creations on their Lands. These Lands can be bound to a sandbox in the Matrix Network which has its own compute and storage resources. These resources allow landowners and creators to govern the visual appearance, inner properties, and lifecycle logic of the Land's creations, ultimately resulting in the production of an immersive 3D application that can operate in perpetuity in the Matrix World cyberspace. In Matrix World, users can take advantage of standard 3D open-world features such as building 3D architectures, hosting virtual meetings, exhibiting digital assets (e.g., NFTs), etc., along with more advanced functionality such as creating and hosting 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 in the metaverse by eliminating the boundary between blockchains and building a nextgeneration 3D open-world DApp platform on top of Matrix World.