TypeScript 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, and stay up to date via our blog and twitter account.

There are many ways to contribute to TypeScript.

• Submit bugs and help us verify fixes as they are checked in.
• Review the source code changes.
• Engage with other TypeScript users and developers on StackOverflow.
• Join the #typescript discussion on Twitter.
• Contribute bug fixes.
• Read the language specification (docx, pdf).

• Quick tutorial
• Programming handbook
• Language specification
• Homepage

In order to build the TypeScript compiler, ensure that you have Git and Node.js 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. 

node built/local/tc.js hello.ts

For details on our planned features and future direction please refer to our roadmap.