Bulma is an open source, simple and modern CSS framework, which depend on flexbox module (it is used for developing responsive layout structure).
Bulma was published in the year 2016 and distributed under MIT license. The current version of Bulma is 0.7.1, was released on April 18, 2018.
Bulma is very easy to learn and setup. It is built with SASS and divided by 39 .sass files. Code can be customized easily by dividing into separate files and it allows customizing the part of application to get the expected result.
It is a lightweight, modern CSS framework, which uses Flexbox.
It contains mobile first styles in a single file, instead of in separate files.
It is customizable and modularizable.
It provides responsive design for desktops, tablets and mobiles.
It uses minimal HTML code, which makes easy to read and write the code.
It is a new framework, which is not as large of a community.
It has less documentation and need some minor improvement.
This framework is still in development phase.