Lesson 1.1: What is HoloScript?

Welcome to HoloScript Academy! In this first lesson, you'll learn what HoloScript is, why it was created, and what makes it unique for VR/XR development.

Learning Objectives

By the end of this lesson, you will:

• Understand what HoloScript is and its purpose
• Know the key features that make HoloScript unique
• Understand when to use HoloScript vs. traditional game engines

What is HoloScript?

HoloScript is a full programming language designed specifically for creating VR and XR (Extended Reality) experiences. Purpose-built for spatial computing, HoloScript features a dual parser (TypeScript + Rust/WASM), its own AST, type system, standard library, LSP, package ecosystem, and compiles to 18+ targets:

• Declarative 3D scenes - Describe what you want, not how to build it
• Built-in VR interactions - Grabbing, pointing, and physics out of the box
• Multiplayer-first - Networking is a core feature, not an afterthought
• AI-ready - First-class support for AI behaviors and NPCs

A Simple Example

Here's what HoloScript looks like:

composition "My First VR Room" {
  // A glowing composition that users can grab
  composition welcomecomposition {
    @grabbable
    @glowing { color: "#4A90D9", intensity: 0.8 }

    position: [0, 1.5, -2]
    scale: 0.15
    color: "#4A90D9"

    onGrab: {
      console.log("You grabbed the orb!")
    }
  }
}

Compare this to creating the same scene in a traditional game engine - you'd need hundreds of lines of code dealing with input systems, rendering, physics setup, and more.

Key Concepts

1. Compositions

A composition is the root container for your VR scene. Think of it as a "world" that contains all your objects:

composition "Scene Name" {
  // Objects go here
}

2. Orbs (Objects)

Orbs are the building blocks of your scene - 3D objects with properties:

composition myObject {
  position: [x, y, z]
  scale: 1.0
  color: "#FF0000"
}

3. Traits

Traits are reusable behaviors you add with the @ symbol:

composition button {
  @grabbable        // Can be picked up
  @physics          // Has physical properties
  @networked        // Syncs across multiplayer
}

4. Event Handlers

Event handlers respond to user interactions:

composition button {
  onClick: {
    // Do something when clicked
  }

  onGrab: {
    // Do something when grabbed
  }
}

Why HoloScript?

Before HoloScript

Creating a simple grabbable object in Unity or Unreal requires:

• Setting up the XR Interaction Toolkit
• Creating a C# script for grab behavior
• Configuring Rigidbody physics
• Setting up layers and interaction masks
• Writing networking code for multiplayer

With HoloScript

composition cube {
  @grabbable
  @physics
  @networked
}

That's it. Three lines, fully functional.

The HoloScript Ecosystem

HoloScript isn't just a language - it's an ecosystem:

Component	Description
@holoscript/core	Parser, compiler, and runtime
@holoscript/cli	Command-line tools
@holoscript/lsp	IDE support via Language Server Protocol
VS Code Extension	Syntax highlighting, completions, debugging
IntelliJ Plugin	JetBrains IDE support

When to Use HoloScript

Use HoloScript when:

• Building social VR experiences
• Creating multiplayer games
• Prototyping VR ideas quickly
• Building tools for non-programmers

Consider alternatives when:

• You need extremely low-level control
• Building AAA game graphics
• Working with existing Unity/Unreal projects

Exercise: Explore HoloScript

1. Visit the HoloScript Playground
2. Try modifying the example scene
3. Change the orb's color and position
4. Add a second composition to the scene

Summary

• HoloScript is a full programming language for VR/XR development
• It uses compositions, orbs, traits, and event handlers
• The @ symbol adds behaviors (traits) to objects
• HoloScript dramatically reduces code compared to traditional engines

Next Lesson

In Lesson 1.2: Installation & Setup, you'll install HoloScript and set up your development environment.

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Time to complete: ~15 minutes Difficulty: Beginner Prerequisites: None