Awesome

To run

1. sudo npm install -g typescript (if you havn't already)
2. sudo npm install -g JSV (needed for validation)
3. git clone https://git01.codeplex.com/typescript
4. tsc --out ifacejson.js typescript/src/compiler/parser.ts convert.ts
5. tsc example.ts
6. node example.js

Superseded by: https://github.com/lbovet/typson

A similar converter from TypeScript to JSON Schema, implemented in Java instead of JS, can be found on https://github.com/vorburger/eclipse-typescript-xtext + https://github.com/lbovet/wtype.