Web Essentials has LESS support!

At http://vswebessentials.com/ get "Web Essentials 2013 for Update 3" which will require that you first have Update 3 which you may get like so:

1. go to "Extensions and Updates..." at the TOOLS menu in Visual Studio 2013
2. click on "Updates" at the left of the "Extensions and Updates" dialog box which appears
3. find Update 3 and click its "Update" button

Once you have everything and it works, when you make a change in a .less file and then save the file, the appropriate updates will cascade to your .css files which are complied from .less files! You will see that familiar "This file has been modified outside of the source editor. Do you want to reload it?" alert to which you will answer "Yes" of course. I think Web Essentials also does .js to minified .js stuff too. This means the death of Chirpy I'd imagine.