Frameworks Using Less

UI/Theme Frameworks and Components
Ant Design An enterprise-class UI design language and React-based implementation.
Balloon.css Simple tooltips made of pure CSS
Bootflat Open source Flat UI KIT based on Bootstrap
BootPress A PHP Framework with a built in Blog and Flat File CMS
Bootstrap Front-end framework for developing responsive, mobile first projects on the web
Bootswatch Collection of free themes for Bootstrap
Cardinal Small "mobile first" CSS framework for front-end developers who build responsive web applications
Flat UI Free Theme and framework for Bootstrap
Fomantic-UI The official community fork of Semantic-UI
Ink set of tools for quick development of web interfaces
Metro UI CSS Set of styles to create a site with an interface similar to Windows 8
Petal A modern, light CSS UI framework developed at Shakr
Pre CSS framework
prelude Lightweight, responsive and extensible front-end framework
React Suite 🧱 A suite of React components
Schema Light, responsive, and lean frontend UI framework
Semantic UI UI component framework based around useful principles from natural language
Strapless CSS boilerplate/framework for HTML elements, mixins library for patterns and color
UIkit Lightweight and modular front-end framework for developing web interfaces
ngBoilerplate An opinionated kickstarter for AngularJS projects
Wee Lightweight front-end framework for logically building complex, responsive web projects

Grid Systems
Flexible Grid System
adaptGrid
Fluidable
Golden Grid System
Less Zen Grid
Order.less
responsibly
Responsive Boilerplate
Semantic.gs

Mixin Libraries
3L Mixins library
animate Library of CSS3 keyframe animations
Clearless Collection of mixins
Css3LessPlease Conversion of css3please.com to Less mixins
CssEffects Collection of CSS style effects
Cssowl Mixin library
cube.less Animated 3D cube using only CSS
est Mixin library
Hexagon Generate CSS hexagons with custom size and color
homeless Mixin library
LESS Elements Set of mixins
LESS Hat Mixins library
lessley A jasmine like testing suite written in pure Less
Lessmore Mixins library. Cross-browser support for the CSS3 features and more
LESS-bidi Set of mixins for creating bi-directional styling
LESS-Mix Mixins library
media-query-to-type Media Queries to Media Types with Less
More-Colors.less Variables for easier color manipulation while you design in the browser
more-less Mixin lib supporting Less 1.7
More.less Mixins, animations, shapes and more
more-or-less for-loops and other functions + css3 mixins
normalize.less Modularized famous normalize.css using Less
Oban Collection of mixins
Preboot Collection of variables and mixins. The precursor to Bootstrap
prelude-mixins Collection of mixins
Shape.LESS Collection of mixins for various shapes
tRRtoolbelt.less Mixins and functions for common actions
Tuesday.less CSS Animation mixins library
Less Style Library A collection of variables and LESS namespaced mixins

Editors and Editor Plugins

Also see: GUIs for Less

Editors and IDEs

Sublime Text 2 & 3

Eclipse

Komodo Edit/IDE

Visual Studio

Dreamweaver

Notepad++ 6.x

Browser extensions


Less.js Plugins

Available Less plugins. Find more at GitHub and NPM Registry

Postprocessor/Feature Plugins
Autoprefixer Add vendor prefixes
CSScomb Beautify/format
clean-css Compress/minify
CSSWring Compress/minify
css-flip Generate left-to-right (LTR) or right-to-left (RTL) CSS
functions Write custom Less functions in Less itself
group-css-media-queries Group CSS media queries
inline-urls Convert url() to a call to data-uri()
lesshint Lint your Less
lists Lists/arrays manipulation (incl. loops)
pleeease Postprocess using pleeease
rtl Reverse from ltr to rtl
variables-output Export top-level variables to a JSON file

Preprocessors
sass2less Import and convert Sass/SCSS files into your Less code (incl. variables, mixins and more)

Import Plugins
bower-resolve Import from a Bower package
glob Globbing support in Less imports
npm-import Import from npm packages
resolve-blocks Going up a tree to find specified component

Function Libraries
advanced-color-functions Functions to find more contrast colors
cubehelix A cubehelix function
lists Lists/arrays manipulation functions
urlencode URL Encode function
util A set of utility functions

Framework Importers
Bootstrap Bootstrap
Cardinal Cardinal
Flexbox Grid Flexbox Grid
Flexible Grid System Flexible Grid System
Ionic Ionic
Lesshat Lesshat
Skeleton Skeleton

GUIs for Less

Tip: try out the different Less tools available for your platform to see which one meets your needs.

This page focuses on GUI compilers. For command line usage and tools see Command Line Usage.

Cross platform

Crunch 2!

The editor and compiler for awesome people.

Crunch 2 is a cross-platform (Windows, Mac, and Linux) editor with integrated compiling. If you work with large Less projects, you should definitely try it out, as you only need the free version for Less files. Available at: https://getcrunch.co/.

Crunch screenshot

Koala

Koala is a cross-platform GUI application for compiling less, sass and coffeescript.

Features: cross platform, compile error notification supports and compile options supports.

Get more info: http://koala-app.com/

koala screenshot

Prepros

Prepros is a tool to compile Less, Sass, Compass, Stylus, Jade and much more.

Get more info at https://prepros.io/

Prepros screenshot

Specific platforms

Windows

WinLess

WinLess started out as a clone of Less.app, it takes a more feature-complete approach and has several settings. It also supports starting with command line arguments.

Get more info: http://winless.org

WinLess screenshot

OS X

CodeKit

CodeKit is the successor to LESS.app, and supports Less among many other preprocessing languages, such as SASS, Jade, Markdown, and many more.

Get more info: http://incident57.com/codekit

CodeKit screenshot

LiveReload

CSS edits and image changes apply live. CoffeeScript, SASS, Less and others just work.

Get more info: http://livereload.com

LiveReload screenshot

Linux

Plessc

Plessc is a gui fronted made with PyQT.

Auto compile, log viewer, open the less file with the editor chosen, settings for compile the file. Get more info: https://github.com/Mte90/Plessc

Plessc screenshot


Online Less Compilers
less2css.org Online Integrated Development Environment (IDE) that is hosted in a browser allowing users to edit and compile Less to CSS in real-time.
winless.org/online-less-compiler This Online Less Compiler can help you to learn Less. You can go through the examples below or try your own Less code.
lesstester.com Online compiler for Less CSS.
leafo.net/lessphp/editor lessphp live demo.
estFiddle Online Less compiler providing live demo for Less and est. Allowing users to switch among all versions of Less after 1.4.0 with optional est/Autoprefixer functionalities.
BeautifyTools Less Compiler Online Less compiler with optional formatting and minification at BeautifyTools
Less WebCompiler The most configurable Less web compiler on the internet, it allows to render the CSS output with your own Coding Standards!

Online Web IDEs/Playgrounds with Less support
CSSDeck Labs CSSDeck Labs is a place where you can quickly create some experiments (or testcases) that involves HTML, CSS, JS code.
CodePen CodePen is a playground for the front end side of the web.
Fiddle Salad An online playground with an instantly ready coding environment.
JS Bin JS Bin is a webapp specifically designed to help JavaScript and CSS folk test snippets of code.
jsFiddle Online Web Editor

Third Party Compilers

Node.js Tools

Other Technologies

Wro4j Runner CLI Download the wro4j-runner.jar file and run the following command:

java -jar wro4j-runner-1.5.0-jar-with-dependencies.jar --preProcessors lessCss

More details can be found here: Wro4j Runner CLI

CSS::LESSp

http://search.cpan.org/~drinchev/CSS-LESSp/ 

lessp.pl styles.less > styles.css

Windows Script Host

Note - the official Less node runs on windows, so we are not sure why you would use this.

Less.js for Windows with this usage:

cscript //nologo lessc.wsf input.less [output.css] [-compress]

or

lessc input.less [output.css] [-compress]

dotless

dotless for Windows can be run like this:

dotless.Compiler.exe [-switches] <inputfile> [outputfile]

Also see:


Ports of Less.js

Java

.Net

PHP

Python

Ruby

Go

Know of another port that should be added to this list? Please let us know.