The typescript playground[1], which lets you try TypeScript in your browser, looks so professional and finished when compared to CoffeeScript[2] or Dart[3]. As someone who attempted a half-baked Rust to JavaScript transpiler[4], I am floored with the packaging of TypeScript (tutorials, specs, editor integrations, npm, playground). At the moment, the only missing feature that my jealousy could point out is autoscrolling (see lexer example in my demo)!<p>By the way, is playground using v1.0?<p>[1] <a href="http://www.typescriptlang.org/Playground/" rel="nofollow">http://www.typescriptlang.org/Playground/</a><p>[2] <a href="http://coffeescript.org/" rel="nofollow">http://coffeescript.org/</a> (Try CoffeeScript tab)<p>[3] <a href="http://try.dartlang.org/" rel="nofollow">http://try.dartlang.org/</a><p>[4] <a href="http://bilalhusain.com/rust-lexer/syntax.html" rel="nofollow">http://bilalhusain.com/rust-lexer/syntax.html</a>