Bootstrap 4 is coming soon
Bootstrap is the most popular front-end framework in the world for developing responsive, mobile first projects on the web.
Bootstrap 4 have pretty huge additions:
- Moving from LESS to Sass
- Adding optional Flexbox support
- New ultra-flexible card component
- More flexible navbar component
So stay patient there's nothing stopping you use Bootstrap 4 already you just need to be prepare to hit a few bugs along the way. If you are a developer you can always jump into the issue queue and do some testing.