Less in general

The parser libs may ship dedicated information based on the language you want to use.

Frontend

Example TYPOScript:

page.includeCSS.testLess = EXT:dyncss_test/Resources/Public/Stylesheets/Example.less

Example Overrides (dynamic color settings, dynamic image overrides):

plugin.tx_dyncss {
	register = LOAD_REGISTER
	register {
		inputColor1.cObject = TEXT
		inputColor1.cObject {
			value = {$lessColorScheme}
			split {
				token.char = 124
				returnKey = 0
			}
		}
		inputColor2 < .inputColor1
		inputColor2.cObject.split.returnKey = 1
	}
	overrides {
		inputColor1 = TEXT
		inputColor1 {
			data = register:inputColor1
		}
		inputColor2 = TEXT
		inputColor2 {
			data = register:inputColor2
		}
		logo = IMG_RESOURCE
		logo {
			stdWrap.wrap = url("|")
			file = GIFBUILDER
			file {
				XY = [20.w],[20.h]
				20 = IMAGE
				20.file = GIFBUILDER
				20.file {
					XY = 128,22
					backColor.data = register:inputColor1
				}
				20.mask = EXT:example/css/colors/less/images/logo_sw.png
			}
		}
	}
	registerReset = RESTORE_REGISTER
}

Example less file:

	@linkColor: blue;
	@logo: url(someWeirdUrl);

	a {
		color: @linkColor;
	}

	h1 {
		a {
			color: lighten(@linkColor, 20%);
		}
	}
	#logo {
		background-image:@logo
	}

Backend: Include in backend.php

To see how it works, please take a look into dyncss_test.