The Leo Programming Language
Leo is a functional, statically-typed programming language built for writing private applications.
## Table of Contents
* [1. Overview](#1-overview)
* [2. Build Guide](#2-build-guide)
* [2.1 Install Rust](#21-install-rust)
* [2.2a Build from Crates.io](#22a-build-from-cratesio)
* [2.2b Build from Source Code](#22b-build-from-source-code)
* [3. Quick Start](#3-quick-start)
* [4. Documentation](#4-documentation)
* [5. Contributing](#5-contributing)
* [6. License](#6-license)
## 1. Overview
Welcome to the Leo programming language.
Leo exists to provide a simple high-level language that abstracts low-level cryptographic concepts and makes it easy to
integrate private applications into your stack. Leo compiles to R1CS circuits making zero-knowledge proofs practical.
With Leo, you can support zero-knowledge tokens, private stable coins, and decentralized marketplaces.
The syntax of Leo is influenced by JavaScript, Python, Scala, and Rust with a strong emphasis on readability and ease-of-use.
Leo provides developers with never before seen tools to sanity check circuits including unit tests, integration tests, and console functions.
Leo is one part of a greater ecosystem for building private applications on [Aleo](https://aleo.org/). If your goal is to build a user experience
on the web that is both truly personal and truly private, then we recommend downloading the [Aleo Studio IDE](https://aleo.studio/)
and checking out the [Aleo Package Manager]().
## 2. Build Guide
### 2.1 Install Rust
We recommend installing Rust using [rustup](https://www.rustup.rs/). You can install `rustup` as follows:
- macOS or Linux:
```bash
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
```
- Windows (64-bit):
Download the [Windows 64-bit executable](https://win.rustup.rs/x86_64) and follow the on-screen instructions.
- Windows (32-bit):
Download the [Windows 32-bit executable](https://win.rustup.rs/i686) and follow the on-screen instructions.
### 2.2a Build from Crates.io
We recommend installing Leo this way. In your terminal, run:
```bash
cargo install leo
```
Now to use Leo, in your terminal, run:
```bash
leo
```
### 2.2b Build from Source Code
Alternatively, you can install Leo by building from the source code as follows:
```bash
# Download the source code
git clone https://github.com/AleoHQ/leo
cd leo
# Build in release mode
$ cargo build --release
```
This will generate an executable under the `./target/release` directory. To run snarkOS, run the following command:
```bash
./target/release/leo
```
## 3. Quick Start
Use the Leo CLI to create a new project
```bash
# create a new `hello_world` Leo project
leo new hello_world
cd hello_world
# build & setup & prove & verify
leo run
```
The `leo new` command creates a new Leo project with a given name.
The `leo run` command will compile the main program, generate keys for a trusted setup, fetch inputs, generate a proof and verify it.
Congratulations! You've just run your first Leo program.
## 4. Documentation
* [Hello World - Next Steps](https://developer.aleo.org/developer/getting_started/hello_world)
* [Leo Language Documentation](https://developer.aleo.org/developer/language/layout)
* [Leo CLI Documentation](https://developer.aleo.org/developer/cli/new)
* [Homepage](https://developer.aleo.org/developer/getting_started/overview)
## 5. Contributing
Please see our guidelines in the [developer documentation](https://developer.aleo.org/developer/additional_material/contributing)
Thank you for helping make Leo better!
## 6. License
[](./LICENSE.md)