TTSL stands for Tiny Typescript Standard Library. It's originally an attempt to learn Typescript. It contains in particular a of typed collections (list, map, set, etc.).

First thing first: retrieving local node modules listed in package.json. You can simply do it by:

npm install

Then set your favorite IDE (Webstorm, VS Code, etc.) to understand ES6 syntax.

Finally you can compile/transpile all .ts files into ES5 by doing:

tsc --target es5 --modules commonjs