The Bootstrap team has announced that after years of development Bootstrap 4 is finally here. Bootstrap is an open source toolkit for developing HTML, CSS and JavaScript applications.  The latest release makes some key improvements over the previous versions.

“Since our last beta, we’ve been hard at work stabilizing a few key pieces of our CSS, polishing our documentation, adding some extra surprises, and planning for our follow-up releases. We still have some kinks to iron out, but nothing’s going to stop us from shipping a stable release,” the Bootstrap team wrote in a blog post.

Version 4.0 includes updated print styles and utility classes. Printed pages are now rendered in a different way to ensure that they are reasonably sized instead of just being rendered as mobile devices. The print display utilities include new display values, which match the standard display utilities.

This new version also includes some new additive border utilities, which defaults to a solid 1px light gray border. This improvement enables developers to add borders more quickly, according to the team.

In addition, Bootstrap 4 contains some updated Sass maps ($spacers and $sizes) that will allow more customization by allowing developers to add, remove, or replace key-value pairs across the CSS code.

The team has also added documentation to the theming docs on CSS variables for developers that don’t want to use Sass. “Our intent is to distill and document all the things we keep in our heads while writing code, building linters, and debugging. Much of this is focused on concepts and strategies for writing responsive CSS, using simple selectors, and limiting how much JavaScript one needs to write,” the Bootstrap team wrote. In addition, Bootstrap themes has been expanded to include ten new themes.

The next release of Bootstrap will be v4.1, and will be focused on small new features, utilities, and responsive font sizes. “We aim to make RTL part of an upcoming minor release depending on overall scope. It’s taken us far too long to commit to this, but we’re on it. Our current plan is focused on implementing this into our build tools and components so you conditionally serve, for example, bootstrap.min.css or bootstrap-rtl.min.css. Weigh in on the open issue please with any feedback; when we’re ready, we’ll tee up a fresh pull request with help from the community,” the team wrote.