# TypeScript

[TypeScript](http://www.typescriptlang.org/) is a language for application-scale JavaScript. TypeScript adds optional types, classes, and modules to JavaScript. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the [playground](http://www.typescriptlang.org/Playground), and stay up to date via [our blog](http://blogs.msdn.com/typescript) and [twitter account](https://twitter.com/typescriptlang).


## Contribute

There are many ways to [contribute](https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md) to TypeScript.
* [Submit bugs](https://github.com/Microsoft/TypeScript/issues) and help us verify fixes as they are checked in.
* Review the [source code changes](https://github.com/Microsoft/TypeScript/pulls).
* Engage with other TypeScript users and developers on [StackOverflow](http://stackoverflow.com/questions/tagged/typescript). 
* Join the [#typescript](http://twitter.com/#!/search/realtime/%23typescript) discussion on Twitter.
* [Contribute bug fixes](https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md).
* Read the language specification ([docx](http://go.microsoft.com/fwlink/?LinkId=267121), [pdf](http://go.microsoft.com/fwlink/?LinkId=267238)).


## Documentation

*  [Quick tutorial](http://www.typescriptlang.org/Tutorial)
*  [Programming handbook](http://www.typescriptlang.org/Handbook)
*  [Language specification](http://go.microsoft.com/fwlink/?LinkId=267238)
*  [Homepage](http://www.typescriptlang.org/)

## Building

In order to build the TypeScript compiler, ensure that you have [Git](http://git-scm.com/downloads) and [Node.js](http://nodejs.org/) installed.

Clone a copy of the repo:

```
git clone https://github.com/Microsoft/TypeScript.git
```

Change to the TypeScript directory:

```
cd TypeScript
```

Install Jake tools and dev dependencies:

```
npm install -g jake
npm install
```

Use one of the following to build and test:

```
jake local           # Build the compiler into built/local 
jake clean           # Delete the built compiler 
jake LKG             # Replace the last known good with the built one.
                     # Bootstrapping step to be executed when the built compiler reaches a stable state.
jake tests           # Build the test infrastructure using the built compiler. 
jake runtests        # Run tests using the built compiler and test infrastructure. 
                     # You can override the host or specify a test for this command. 
                     # Use host=<hostName> or tests=<testPath>. 
jake baseline-accept # This replaces the baseline test results with the results obtained from jake runtests. 
jake -T              # List the above commands. 
```


## Usage

```shell
node built/local/tsc.js hello.ts
```


## Roadmap

For details on our planned features and future direction please refer to our [roadmap](https://github.com/Microsoft/TypeScript/wiki/Roadmap).