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A collection of LESS mixins and variables for writing better CSS.

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Statistics on preboot

Number of watchers on Github 1739
Number of open issues 7
Average time to close an issue 8 months
Main language CSS
Average time to merge a PR 24 days
Open pull requests 4+
Closed pull requests 14+
Last commit about 5 years ago
Repo Created over 9 years ago
Repo Last Updated over 2 years ago
Size 504 KB
Homepage http://getpreboot...
Organization / Authormdo
Latest Releasev2.1.0
Page Updated
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Preboot 2

Preboot is a collection of LESS mixins and variables for quickly writing CSS. As the precursor to Bootstrap, it serves as a lightweight and interface agnostic approach to jumpstarting your next web project. Use it how you see fit.

Getting started

Preboot requires LESS. Head over to their documentation and familiarize yourself with the project. Once you're up and running, including and using Preboot is a breeze.

  1. Create a new LESS file (e.g., application.less)
  2. Include Preboot via @import "preboot.less";
  3. Start writing your own LESS-flavored CSS

We highly recommend using Preboot in conjunction with Normalize, a powerful tool for more consistent rendering of web components across various browsers and devices.

Bugs and feature requests

Have a bug or a feature request? Please open a new issue. Before opening any issue, please search for existing issues and read the Issue Guidelines, written by Nicolas Gallagher.


Mark Otto

Brief history

Preboot was originally released in March 2011 under the name Bootstrap.less. Sensing the need for a larger and more comprehensive framework, I copped the name and created Bootstrap based on the original variables and mixins work here. To avoid obivous naming issues, I renamed this Preboot and essentially didn't touch the project for two years.

Fast forward two years and I'm backporting many of Bootstrap's variables and mixins back into Preboot as v2.

Disclaimer: Preboot v1 (Bootstrap.less) was released under a Creative Commons license and is still available. Preboot 2 is now under MIT.

Copyright and license


preboot open issues Ask a question     (View All Issues)
  • over 7 years Missing: column-span
  • over 7 years very simple layout creates unnecessary margin
  • over 7 years .size() improvement to replace .square()
preboot open pull requests (View All Pulls)
  • v3
  • Pass media query breakpoint to column mixins
  • simplify media queries for retina-image mixin
  • Fixed a template bug and added support for cache busting and font-faces.
preboot questions on Stackoverflow (View All Questions)
  • Confirming Heroku Preboot
  • How to tell when heroku preboot is live
  • Heroku Preboot Rollover Time
  • How to use Preboot mixins in a Rails project with Twitter Bootstrap
  • Why do the Preboot mixins no longer compile after Less 1.3.1?
preboot list of languages used
preboot latest release notes
v2.1.0 v2.1.0

Quick release to capture the commits added after the v2 release.

v2 Preboot 2

Complete re-engineering of the project. Highlights include:

  • A plethora of useful and customizable variables including grayscale and semantic colors like @black-50 and @brand-success, scaffolding settings like @body-background and @link-color, and typographic shortcuts for font stacks, sizes, headings, and more.
  • A powerful, semantic, and mobile-first grid system to create your own layouts with ease with just three mixins: .make-row(), .make-column(), and .make-column-offset().
  • Several vendor-prefix mixins to streamline writing of common CSS3 functions like transitions, gradients, and more.
  • Several utility mixins for reusing common snippets of code like .clearfix(), .text-truncate(), and more.


v1.0 Bootstrap.less (Preboot 1)

Tagging the latest code as v1 for archiving purposes ahead of the Preboot 2 launch.

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