Helps you create themes faster with sustainable code. With Timber, you write HTML using Mustache-like Templates http://timber.upstatement.com
Timber cleans-up your theme code so, for example, your php file can focus on being the data, while your twig/html file can focus 100% on the HTML and display.
Once Timber is installed and activated in your plugin directory, it gives any WordPress theme the ability to take advantage of the power of Twig and other Timber features.
Nothing. Timber is meant for you to build a theme on. Like the Starkers or _s theme it comes style-free, because you're the style expert. Instead, Timber handles the logic you need to make a kick-ass looking site.
Timber is great for any WordPress developer who cares about writing good, maintainable code. It helps teams of designers and developers working together. At Upstatement we made Timber because not everyone knows the ins-and-outs of the_loop(), WordPress codex and PHP (nor should they). With Timber your best WordPress dev can focus on building the .php files with requests from WordPress and pass the data into .twig files. Once there, designers can easily mark-up data and build out a site's look-and-feel.