Windows9x

Windows9X is the operating system of future's past. What if Windows 98 could generate any application that you wanted on the fly? You enter the description of a program you want inside of the run dialog and the OS creates that for you on the fly. This is an experiment in end user programming and seeing what it could be like if an OS could write applications for you as you need them.

filesystem.mp4

Getting started

Create a .env file with the following in the root directory:

ANTHROPIC_API_KEY=<your-anthropic-api-key>
NEXT_PUBLIC_LOCAL_MODE=true
# Optional Replicate API key for icon generation
REPLICATE_API_TOKEN=<your-replicate-api-token>

Note: NEXT_PUBLIC_LOCAL_MODE disables the use of 3rd party services other than your modal provider.

1. Install node v21 or greater
2. Install bun
3. Run bun install
4. Run bun run dev
5. Navigate to http://localhost:3000

How does this work?

When you enter a description of an application, an LLM is prompted to generate an HTML file that looks like a windows 98 application. This is done by injecting 98.css into the page as we stream in the result. This is rendered inside of an iframe that is rendered inside of a window.

In addition applications have access to a limited OS API that allows for saving/reading files, reading/writing from the registry, and prompting an LLM.

OS API

This is the api that applications have access to in case it helps with prompting:

declare global {
  // Chat lets you use an LLM to generate a response.
  var chat: (
    messages: { role: "user" | "assistant" | "system"; content: string }[]
  ) => Promise<string>;
  var registry: Registry;

  // If the application supports saving and opening files, register a callback to be called when the user saves/opens the file.
  // The format of the file is any plain text format that your application can read. If these are registered the OS will create
  // the file picker for you. The operating system will create the file menu for you.

  // The callback should return the new content of the file
  // Used like this:
  // registerOnSave(() => {
  //   return "new content";
  // });
  var registerOnSave: (callback: () => string) => void;

  // Register a callback to be called when the user opens the file
  // The callback should return the content of the file
  // Used like this:
  // registerOnOpen((content) => {
  //   console.log(content);
  // });
  var registerOnOpen: (callback: (content: string) => void) => void;
}

// Uses for the registry:
// - To store user settings
// - To store user data
// - To store user state
// - Interact with the operating system.
//
// If the key can be written by other apps, it should be prefixed with "public_"
interface Registry {
  get(key: string): Promise<any>;
  set(key: string, value: any): Promise<void>;
  delete(key: string): Promise<void>;
  listKeys(): Promise<string[]>;
}

Thanks

I want to thank the following people:

• Scratch - Inspired me by getting Windows 98 to run inside of a VM inside of Websim.
• Nate - Nate and I independently started building the same project. Nate gave me the idea of "chatting with the developer" to change the program.
• Jordan - Make 98.css which is the basis that makes this look like Windows 98.

Demos

Here are a few examples of applications that can be created:

Everything in Windows9X is a file you can generate a program to generate another program

Everything.is.a.file.mp4

Here is an example of an application that is generated that in turn can generate websites.

windows_making_browser.mp4

Creating a natural language SQL prompter

sql.mp4