# LESS

> dynamic stylesheet language

**Wikidata**: [Q1107192](https://www.wikidata.org/wiki/Q1107192)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Less_(style_sheet_language))  
**Source**: https://4ort.xyz/entity/less

## Summary
LESS is a dynamic stylesheet language that extends Cascading Style Sheets (CSS) with features like variables, mixins, and nested rules, making it easier to write and maintain complex stylesheets. It was created by Alexis Sellier and first released in 2009, and its latest stable version is 2.6.1. LESS is free software distributed under the Apache Software License 2.0 and is cross-platform.

## Key Facts
- **Type**: Dynamic stylesheet language that extends CSS.
- **Creator**: Alexis Sellier.
- **Inception**: 2009.
- **Latest stable version**: 2.6.1 (released 2016-03-04).
- **License**: Apache Software License 2.0.
- **Platform**: Cross-platform (works on multiple computing platforms).
- **Dialect of**: Cascading Style Sheets (CSS).
- **Influenced by**: Sass (Syntactically Awesome StyleSheets).
- **Free software**: Distributed under terms allowing users to run, study, change, and distribute it.
- **Website**: [http://lesscss.org](http://lesscss.org).
- **Source code repository**: [GitHub](https://github.com/less/less.js).

## FAQs
### Q: What is LESS used for?
A: LESS is used to write CSS more efficiently by adding features like variables, mixins, and nested rules, which are then compiled into standard CSS for browsers.

### Q: Is LESS still actively maintained?
A: Yes, LESS is still actively maintained, with the latest stable version (2.6.1) released in 2016. The project uses continuous integration for quality assurance.

### Q: How does LESS differ from Sass?
A: LESS and Sass are both CSS preprocessors, but they have different syntaxes. LESS uses a more CSS-like syntax, while Sass offers two syntaxes (SCSS and the indented syntax). Both were influenced by each other.

### Q: Can LESS be used in production?
A: Yes, LESS is widely used in production environments. It is a mature, stable, and well-documented tool with a large community and extensive documentation.

### Q: What are the key features of LESS?
A: Key features of LESS include variables, mixins, nested rules, operators, functions, and imports, which enhance CSS with dynamic capabilities.

## Why It Matters
LESS revolutionized web development by introducing dynamic features to CSS, making stylesheets more maintainable and scalable. Its introduction of variables, mixins, and nested rules allowed developers to write cleaner, more modular code, which was particularly beneficial for large projects. LESS’s cross-platform compatibility and free software licensing made it accessible to a wide range of developers. By simplifying CSS development, LESS played a significant role in improving the efficiency and organization of front-end web development. Its influence can still be seen in modern CSS preprocessors and frameworks, demonstrating its lasting impact on web design.

## Notable For
- **First dynamic CSS preprocessor**: LESS was one of the first tools to extend CSS with dynamic features like variables and mixins, setting a precedent for modern CSS preprocessors.
- **Cross-platform compatibility**: Works seamlessly across different operating systems and browsers.
- **Free software**: Distributed under the Apache Software License 2.0, ensuring it remains open and accessible to all developers.
- **Active community**: Maintained with continuous integration, ensuring high-quality releases and ongoing support.
- **Influence on modern CSS**: Inspired by Sass, LESS helped shape the evolution of CSS preprocessors and influenced modern web development practices.

## Body
### Overview
LESS (Leaner Style Sheets) is a dynamic stylesheet language that extends CSS with features like variables, mixins, and nested rules. It was created by Alexis Sellier and first released in 2009. LESS is free software distributed under the Apache Software License 2.0 and is cross-platform, meaning it can be implemented and operated on multiple computing platforms.

### Features
- **Variables**: LESS allows the use of variables to store values like colors, dimensions, and fonts, making it easier to maintain and update stylesheets.
- **Mixins**: Mixins enable the reuse of groups of CSS properties, reducing redundancy and improving code organization.
- **Nested Rules**: Nested rules allow developers to write CSS in a hierarchical manner, mirroring the structure of HTML, which can improve readability.
- **Operators**: LESS supports mathematical operations, making it easier to manipulate values dynamically.
- **Functions**: LESS includes built-in functions for tasks like color manipulation, string operations, and list handling.
- **Imports**: LESS supports modular development by allowing stylesheets to be split into multiple files and imported as needed.

### Versions
LESS has seen several stable releases, with the latest version being 2.6.1, released on 2016-03-04. Other notable versions include:
- 2.5.1 (2015-05-21)
- 2.5.0 (2015-05-21)
- 2.4.0 (2015-05-21)
- 2.3.1 (2015-01-28)
- 2.3.0 (2015-01-28)
- 2.2.0 (2015-01-04)
- 2.1.2 (2015-01-04)
- 2.1.1 (2015-01-04)
- 2.1.0 (2014-11-23)

### Community and Support
LESS has an active community and is maintained with continuous integration, ensuring high-quality releases. The project is hosted on GitHub, where developers can contribute and report issues. The official website, [http://lesscss.org](http://lesscss.org), provides extensive documentation and resources for users.

### Influence and Legacy
LESS was influenced by Sass and, in turn, influenced the development of modern CSS preprocessors. Its features and syntax have been adopted and adapted by other tools, shaping the evolution of web development. LESS remains a valuable tool for developers seeking to enhance their CSS workflow with dynamic capabilities.

## References

1. [History](https://lesscss.org/about/)
2. [Source](https://github.com/less/less.js/blob/master/LICENSE)
3. [Source](https://github.com/less/less.js/blob/master/CHANGELOG.md)
4. [Release 2.5.1. 2015](https://github.com/less/less.js/releases/tag/v2.5.1)
5. [Release 2.4.0. 2015](https://github.com/less/less.js/releases/tag/v2.4.0)
6. [Release 2.5.0. 2015](https://github.com/less/less.js/releases/tag/v2.5.0)
7. [Release 2.3.1. 2015](https://github.com/less/less.js/releases/tag/v2.3.1)
8. [Release 2.3.0. 2015](https://github.com/less/less.js/releases/tag/v2.3.0)
9. [Release 2.2.0. 2015](https://github.com/less/less.js/releases/tag/v2.2.0)
10. [Release 2.1.2. 2015](https://github.com/less/less.js/releases/tag/v2.1.2)
11. [Release 2.1.1. 2015](https://github.com/less/less.js/releases/tag/v2.1.1)
12. [Release 2.1.0. 2014](https://github.com/less/less.js/releases/tag/v2.1.0)
13. [Release 2.0.0. 2014](https://github.com/less/less.js/releases/tag/v2.0.0)
14. [Release 1.7.5. 2014](https://github.com/less/less.js/releases/tag/v1.7.5)
15. [Release 1.7.4. 2014](https://github.com/less/less.js/releases/tag/v1.7.4)
16. [Release 1.7.3. 2014](https://github.com/less/less.js/releases/tag/v1.7.3)
17. [Release 1.7.2. 2014](https://github.com/less/less.js/releases/tag/v1.7.2)
18. [Release 1.7.1. 2014](https://github.com/less/less.js/releases/tag/v1.7.1)
19. [Release 1.7.0. 2014](https://github.com/less/less.js/releases/tag/v1.7.0)
20. [Release 1.6.3. 2014](https://github.com/less/less.js/releases/tag/v1.6.3)
21. [Release 1.6.2. 2014](https://github.com/less/less.js/releases/tag/v1.6.2)
22. [Release 1.6.1. 2014](https://github.com/less/less.js/releases/tag/v1.6.1)
23. [Release 1.6.0. 2014](https://github.com/less/less.js/releases/tag/v1.6.0)
24. [Release 1.5.1. 2014](https://github.com/less/less.js/releases/tag/v1.5.1)
25. [Release 1.5.0. 2014](https://github.com/less/less.js/releases/tag/v1.5.0)
26. [Release 1.4.0. 2013](https://github.com/less/less.js/releases/tag/v1.4.0)
27. [Release 1.4.1. 2013](https://github.com/less/less.js/releases/tag/v1.4.1)
28. [Release 1.4.2. 2013](https://github.com/less/less.js/releases/tag/v1.4.2)
29. [Release 2.7.2. 2017](https://github.com/less/less.js/releases/tag/v2.7.2)
30. [Source](https://github.com/less/less.js/releases/tag/v3.8.1)
31. [Source](https://github.com/less/less.js/releases/tag/v3.8.0)
32. [Source](https://github.com/less/less.js/releases/tag/v3.9.0)
33. [Source](https://github.com/less/less.js/releases/tag/v3.10.0)
34. [Source](https://github.com/less/less.js/releases/tag/v3.10.1)
35. [Source](https://github.com/less/less.js/releases/tag/v3.10.3)
36. [Source](https://github.com/less/less.js/releases/tag/v3.11.0)
37. [Source](https://github.com/less/less.js/releases/tag/v3.11.1)
38. [Release 4.0.0. 2020](https://github.com/less/less.js/releases/tag/v4.0.0)
39. [Release 4.1.0. 2021](https://github.com/less/less.js/releases/tag/v4.1.0)
40. [Release 4.1.1. 2021](https://github.com/less/less.js/releases/tag/v4.1.1)
41. [Source](https://github.com/less/less.js/releases/tag/v4.1.3)
42. [Release 4.1.2. 2021](https://github.com/less/less.js/releases/tag/v4.1.2)
43. [Release 4.2.0. 2023](https://github.com/less/less.js/releases/tag/v4.2.0)
44. [Release 4.2.1. 2024](https://github.com/less/less.js/releases/tag/v4.2.1)
45. [Release 4.2.2. 2025](https://github.com/less/less.js/releases/tag/v4.2.2)
46. [Release 4.3.0. 2025](https://github.com/less/less.js/releases/tag/v4.3.0)
47. [Release 4.4.0. 2025](https://github.com/less/less.js/releases/tag/v4.4.0)
48. [Release 4.4.1. 2025](https://github.com/less/less.js/releases/tag/v4.4.1)
49. [Release 4.4.2. 2025](https://github.com/less/less.js/releases/tag/v4.4.2)
50. [Release 4.5.1. 2026](https://github.com/less/less.js/releases/tag/v4.5.1)