I am developing multilingual site (English and Arabic) in Drupal 8. I want to use bootstrap or zurb foundation, which out of these is good for developing Right to left theme. Site will mainly work in Arabic.
"Foundation was built to support right-to-left text direction out of the box, but you'll need to make a couple of adjustments to your markup and Sass to get everything up and running." This is just some minor changes, nothing special. For bootstrap there's a special version that is focused on RTL support: https://github.com/Kaakati/RTL_Bootstrap