Bootstrap 4 Alpha 6 added flexbox support by default, this is awesome but with no solid Flexbox polyfill for good 'ol Internet Explorer some people might be put off. bootstrap4-noflex removes the flexbox support as a drop in CSS file to keep IE happy.
We use it on our AppStrap Bootstrap 4 theme, check out a demo here: http://bit.ly/1yvkm1Q
Created by Tom James for Themelize.me.