To this end, when beginning to assemble what will eventually become the MOJ Front-End Toolkit we needed to decide on a pattern for including JS files and modules in our sites, so as a starting point we selected Heisenberg.js. It's not a framework or library in itself, but a pattern/methodology for organising your files and we're liking it so far. It provides a defined structure for each module and a standardised way of including modules in our projects. We're not using the whole Heisenberg project, just the module structure, and to further strengthen the idea of consistency we're also using a slightly amended coding style from Idiomatic.js.
If you'd like to know more, the addendum to this post breaks down the JS with an actual example.