What do you guys think about TypeScript? Does it worth time to learn the syntax? Also what is the relation between Angular 2 and TypeScript?

The syntax is pretty straight forward. Mostly it's es6 with types. In my opinion worth it. Especially in larger project with many data types it makes live much easier!

You should definitely try it. If you're familiar with C#, you're half way there. A good part of Angular 2 is written in Typescript.

Worth it. Jump directly into typescript@2 though! I like its strong typechecks, esp. with `strictNullChecks` and `noImplicitAny` set to true in my `tsconfig`. I just wished more checks would also be applied at runtime and not only at compile time, yet I currently prefer TypeScript over JavaScript anyday. Just be sure to transpile into a different `outdir` to not get confused by all the *.ts, *.js, and *.js.map files mundled together. And for a lib's typings management rather use npm and the definitly types `@types/{packageName}` packages instead of typings.

One day when you will find a bug in your JavaScript that took u days, you'll regret not using Typescript.

Speaking from experience.