Recently, I’ve been curious about “Holochain” - a distributed computing technology and framework designed to enable decentralized applications (dApps) to run on a peer-to-peer network without the need for centralized servers. It was created by Arthur Brock and Eric Harris-Braun and first released in 2018.

Unlike traditional blockchain-based systems, Holochain does not rely on a global consensus mechanism or a global ledger. Instead, it uses a distributed hash table (DHT) and cryptographic signatures to ensure data integrity and security. This allows applications to run on a peer-to-peer network of nodes, each running their own copy of the application code and data.

Holochain is designed to be lightweight and efficient, with low latency and high scalability. It can run on a variety of devices, from low-powered smartphones to powerful servers, and is designed to support a wide range of use cases, including social networks, marketplaces, and identity systems.

One of the key features of Holochain is its ability to support agent-centric computing, where each node on the network is treated as an autonomous agent with its own identity, data, and rules. This allows for greater flexibility and adaptability in the design of decentralized applications, as well as greater privacy and security for users.

Overall, Holochain is a promising technology for enabling decentralized applications to run on a peer-to-peer network without the need for centralized servers. It offers a lightweight, efficient, and flexible framework for building and deploying dApps, and could help to promote a more decentralized and secure internet.

Holochain vs IPFS/Bittorrent

Holochain, IPFS (InterPlanetary File System), and BitTorrent are all decentralized computing technologies, but they differ in their approach and focus.

IPFS is primarily designed for decentralized storage and sharing of files, using a content-addressed system to store and retrieve files across a distributed network of nodes. IPFS is optimized for efficient data sharing and supports versioning and deduplication of data. Holochain, on the other hand, is designed to support the creation of decentralized applications that can run on a peer-to-peer network of nodes without the need for centralized servers.

BitTorrent is a peer-to-peer protocol for sharing large files, typically used for distributing files such as movies, music, and software. Unlike IPFS and Holochain, BitTorrent does not provide a framework for building decentralized applications. Instead, it focuses on efficient and scalable file sharing using a distributed network of nodes.

One of the key differences between Holochain and IPFS/BitTorrent is that Holochain is designed to support agent-centric computing, where each node on the network is treated as an autonomous agent with its own identity, data, and rules. This allows for greater flexibility and adaptability in the design of decentralized applications, as well as greater privacy and security for users.

Overall, while IPFS and BitTorrent are primarily focused on decentralized storage and file sharing, Holochain is designed to support the creation of decentralized applications that can run on a peer-to-peer network without the need for centralized servers, using a framework that supports agent-centric computing.

Installing Holochain

Here are the general steps to install Holochain:

  1. Check the system requirements: Holochain requires a 64-bit operating system (Windows, macOS, or Linux) and a minimum of 4GB of RAM.

  2. Install Rust: Holochain is built on Rust, so you’ll need to install Rust first. You can download Rust from the official website: https://www.rust-lang.org/tools/install.

  3. Install Node.js: Holochain requires Node.js version 12 or later. You can download Node.js from the official website: https://nodejs.org/en/download/.

  4. Install Holochain: You can install Holochain using cargo, which is the Rust package manager. Open a terminal or command prompt and run the following command

    cargo install holochain –force

Hello-world App using Holochain

Here’s an example of how to build a simple “Hello World” HApp in Holochain:

  1. Create a new Holochain app ` holochain init my_happ cd my_happ `
  2. Create a new zome ` holochain new zome greeting `
  3. Define the greeting function in the zome/src/lib.rs file ` #[hdk_extern] fn greeting(name: String) -> ExternResult { Ok(format!("Hello, {}!", name)) } `
  4. Build the HApp ` holochain build `
  5. Run the HApp in a conductor ` holochain conductor start `

You may have noticed Holochain specific jargon above: zome and conductor. In Holochain, a zome is a self-contained module of code that defines the data schema, business logic, and validation rules for a specific part of the application. Each zome has its own state, and can communicate with other zomes through the Holochain runtime. A zome can be thought of as a mini-application within the larger Holochain application. It encapsulates a specific domain or feature of the application and provides an API for other zomes to interact with it. A Holochain application can have multiple zomes, each responsible for its own part of the application’s functionality.

A conductor, on the other hand, is the runtime environment for Holochain. It manages the communication between the various zomes running on a given device or network, and provides a secure and reliable distributed computing environment. The conductor manages the networking, storage, and validation of data across zomes and nodes in the Holochain network. It ensures that data is stored and replicated correctly, and that zomes can communicate with each other in a secure and efficient way.