A british medical software company were in dire need of a redesign. The whole system built on Java with jsp templating, it was a little painful. I managed to add bootstrap and start to make things responsive.
One of the biggest challenges was to support IE8 as this was used by hospitals that do not update their computers. This was achieved by using a few different libraries, breakpoints.js, css fillers, old versions of bootstrap, font awesome, modernizr.