The latest version of TypeScript includes of new features in the language, compiler and associated tools. And it comes in the box as part of Visual Studio 2013 and Visual Studio 2015.
When a project reaches a certain size, managing the script modules for a project starts to get tricky. You need to be sure to sequence the scripts in the right order, and you need to start seriously thinking about combining scripts together into a bundle for deployment, so that only one or a very small number of requests are made to load the scripts.
You may also want to load code on the fly, after page load.
RequireJS can help you manage the script modules, load them in the right order, and make it easy to combine the scripts later via the RequireJS optimizer without needing to change your markup. It also gives you an easy way to load scripts after the page has loaded, allowing you to spread out the download size over time.