> For the complete documentation index, see [llms.txt](https://flexecosystem.gitbook.io/flex-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://flexecosystem.gitbook.io/flex-docs/protocol/technical-roadmap-for-the-flex-ecosystem/flex-virtual-machine-fvm.md).

# Flex Virtual Machine (FVM)

Flex is a community-owned platform that rapidly boosts dApp user growth, ensuring the value generated directly benefits the Flex community.

At the heart of the Flex platform lies the Flex Virtual Machine (FVM), a high-performance, Javascript-based execution environment that supports a wide range of smart contract languages and runtimes. The FVM is designed to be blockchain-agnostic, allowing it to be seamlessly deployed on top of any compatible blockchain or layer 2 scaling solution, such as Ethereum, Polkadot, or Cosmos.

Attributes of the FVM include:

1. Multi-language support: The FVM offers support for multiple smart contract languages, including re:Flex, Solidity, Rust, and Javascript, giving developers the flexibility to use their preferred language and toolchain.
2. Gas-efficient execution: The FVM incorporates a variety of optimizations to minimize the gas costs associated with contract execution.
3. Deterministic execution: Ensuring deterministic execution of smart contracts across all nodes in the network is crucial for maintaining consistency and enabling reproducible results. The FVM achieves this through several measures.
4. Upgradability: The FVM supports upgradable contracts, enabling developers to fix bugs, add new features, and improve performance without requiring a hard fork of the underlying blockchain. The upgradability mechanism is based on a proxy pattern, where a master contract delegates call to an implementation contract that can be updated as needed.