2.4.0

• Support for plugins that pre-process (to add libraries silently etc.)
• Empty sourcemaps now work
• Extract and Length functions now ignore comments in a list (more work to come to fix the general problem)
• fragment urls are treated absolute since they refer to the html document
• Extends on a selector joined with & now work better
• Nested mixins work better with !important (regression in 2.3.0)
• The promise dependency is now actually optional (introduced in 2.0.0)
• Files with just \r newlines now process ok (regression in 2.0.0)
• When strict units is off and the unit is 1/x, (e.g. 1 / 12px) the unit output is x, previously nothing (regression in 2.0.0)

v2.3.1

• Fix depends option (regression in 2.3.0)
• Support parent selector (&) used in sub element expression (e.g. :not(.c_&))

v2.3.0

• add isruleset function
• add optional import option, causing less to not fail if file not found
• Fix browsers-side cache.
• Many fixes to import reference - support @support and keyframe
• Selectors now interpolate pseudo selectors (e.g. :@{hover})
• Fix comments missed off if they were at the end of the file
• Fix !important used with parametric mixins
• Emits warnings for extends when the target is not found
• include-path now works on data-uri
• variables and function calls work for path in data-uri
• Fix absolute paths not working on imports sometimes.
• Unicode BOM removed again
• Misc. bug fixes

v2.2.0

• do not apply relative paths to svg-gradient and data-uri functions data-uri output
• using import filename interpolation and import inline together now works
• deprecate the compression option (still works, but outputs a warning unless silent)
• The node version of less now has image-size, image-width, image-height which return the image dimensions of a file
• Fixed an issue that could cause the parse to occur more than once and the callback be called multiple times
• if you are outputting to the console, lessc defaults to silent so warnings do not end up in output
• isunit function supports '' to test if a dimension has no unit
• data-uri function now counts characters after base64 encoding instead of bytes before encoding to determine ie8 support
• fix bug effecting guards on pseudo class selectors
• do not cache on the browser when used with modifyVars
• detection if less does not parse last character in file
• detection of whether a file is css now requires /css, .css, ?css, &css instead of just css. You can still tell less the type of file using import options.
• remove extra new line added to sourcemap entry inline file
• support safari extension
• less.parse now exposes a way to get the AST. We do not recommend you use this unless you need to.

v2.1.2

• Fix for use with requirejs
• Fixes for data-uri function

v2.1.1

• Improved keyword and anonymous usage with the replace function
• Added getCSSAppendage to sourcemap builder to avoid duplication in plugins
• Fix problem with plugins when used with the promises version of render
• If the render callback throws an exception it now propogates instead of calling the callback again with an error

2.1.0

• Fixed isSync option, it was using sync file operations but promises are guaranteed to call back async. We now support promises as a feature rather than the 1st class way of doing things.
• Browser code is now synchronous again, like in v1, meaning it blocks the site until less is compiled
• Some fixes for variable imports which affected filemanagers when synchronous
• Fixed lessc makefile dependencies option
• output now reports back a imports field with an array of imported files
• relative path test for drive names (so windows only) is now case insensitive
• Fix for IE7 - use getChar instead of indexing array
• variables using !important now output !important, which bubbles up to affect the rule
• livereload cache buster is now treated specially
• upgrade dependencies

v2.0.0

• Fixed multiplication in non strict units mode to take the left operand unit, in the case that the unit cannot be resolved
• Some fixes for browser cross-compatibility
• browser tests now pass in IE 8-11 and FF
• added index.js and browser.js in root as shortcuts
• fixed some local variable spellings
• support for @counter-style directive

v2.0.0-b3

some refactoring of browser structure to allow use of api vs normal browser bundle
browser bundle no longer leaks require
browser can now be scoped with just window
browser useFileCache defaults to true, but file cache is now cleared when refreshing or in watch mode

v2.0.0-b2

Imports are now sequenced and so are consistent (previously some complex projects might end up with occasional different orderings)
Imports with variables are better supported - variables can be specified in sub imports
Support for rebeccapurple
Browser can now accept options as attributes on the script tag and the link tags e.g. <script data-verbose="false" src="less.js"...
adding a .less file extension is done in the abstract file manager so it the behaviour can be overridden by certain file managers
Fixed a bug where unquoted urls beginning // e.g. url(//file/file.less) would be incorrectly interpreted (bug introduced in b-1)
lessc plugins can be a function, used as a constructor as well as an object - this to allow the plugin more flexibility to be used programattically