Warning: this release has some breaking changes. If you the old selector expression syntax (eg. Bootstrap 2.3) then it’s recommended to use 0.3.9.

• Add support for ; as argument delimiter
• Add support for passing arguments by name to mixin
• Remove old selector expression syntax ("hello")
• Remove ability to skip arguments by repeating delimiter
• Add built in functions: sin, cos, tan, asin, acos, atan, pow, pi, mod, sqrt, extract
• Fix bug where @arguments was not getting values from ...
• Selector interpolation works inside of brackets in selector
• Fix bug when resolving mixin that has same name as enclosing class
• Duplicate properties are now removed from output

• Fixes compile issue with latest version of bootstrap
• Support nested interpolations
• Support interpolations inside of selectors
• Variables can be inside of a @media declaration — Matt Labrum
• transparent is recognized as a color — Nikolay Yordanov
• Add unit, red, green, blue, constrast functions — Lucas Green, Peter Knight, kaystrobach

• Fix bug preventing Bootstrap’s responsive.less from compiling correctly
• User functions will already recieve colors in color format
• Compressed mode will always compress colors
• Fixed typos

• Overhauled PHP API. See documentation. The old interface is still available, just deprecated and no longer documented.
• Performance optimizations, 25% speed up on average.
• Imports can be inside of mixins.
• Import urls can contain expressions.
• Various bug fixes.

• Added support for @media bubbling, you can now nest media blocks anywhere, and inside of each other.
• Added a option to enable the preservation of /**/ comments. setPreserveComments
• Changed default output formatter to match lessjs
• Change internal structure of numbers and strings, you will have to update your registered functions.
• Disabled color compression, fixed a bug in sorting of properties that prevent your from overwriting same named properties.
• Fixed alpha(opacity=) bug. Better support for IE style colors in filter() values.
• Better fallback for expressions that can’t be evaluated.
• Misc bug fixes, enhanced test coverage significantly (now using travisci)

• Added output formatters, and compressed format
• Support for !important suffix on mixin (nyordanov)
• Added Composer package
• Property assignments moved to top of block (to match lessjs)
• Handful of misc bug fixes, and huge code refactor

• Fixed error about missing is_vararg for some blocks

• Added Selector Expressions
• Allow for mixins to recurse
• Added varags syntax
• Fixed bug with ~ and string interpolation
• ceil function (krues8dr), argb function (Barryvdh)
• Misc bug fixes

• Importing done before evaluating to allow referencing mixins imported from other files before they are defined.
• Fixed spin function to wrap hue around 0-360
• Resulting unit of math expressions matches less.js in all cases
• Division operator handled more like less.js (using property name, see division section of Expressions)
• Mixins look up variables in their lexical scope when being mixed (instead of the target scope)
• Expressions in variables evaluated in referenced scope instead of declared scope
• Infinite loop detection for new evaluation model
• Improved error messages for compile time errors
• Expressions can be placed in @media queries
• Default arguments appear in @arguments
• Tweaked output of color functions to match less.js
• Misc Bug fixes

• Pattern matching
• Guards
• Variable variables
• Testing script works on windows (thanks GerHobbelt)
• Instance of lessc passed to extension functions as second arg
• Fix broken nested import bug
• Misc bug fixes

• New extension function interface without subclassing
• Support for @arguments special variable
• Added built in functions alpha, fade, mix, percentage
• Color keywords are translated to their rgb version when used in expressions and functions
• Misc bug fixes

• compatibility update for lessjs
• changed argument delim to ,
• don’t need a > to delimit mixin path
• added % string escape function
• change string variable interpolation syntax to @{var}
• psuedo classes are not joined automatically when nested
• & can be used anywhere in selector to represent parent
• ~ operator, and e function for unquoting a string

• reimplemented core parsing techniques, 50% speed up
• all css selectors should be functional
• support for @charset @font-face
• & operator for nesting chained blocks
• ! operator for inserting important property
• exposed function api: http://github.com/leafo/lessphp/commit/2fb4296a6a7287ea53e99b73858bfd5a44834cad
• much better number, color, and string parsing support

• rewrote command line tool, plessc, with more logical argument parsing and proper exit codes
• separate blocks of the same name will now merge instead of overwriting each over
• fixed a bug with any type of mixin not searching outside the scope
• updated this webpage

• wrote documentation, see http://leafo.net/lessphp/docs/
• added support for variables inside of strings
• mixins append their data into the block instead of overwriting
• fixed a bug where rgb was being ignored since 0.1.4

• blocks that start with @ are treated as abstract blocks and are not printed out
• all blocks/mixins can now take argument lists (with default args) and be treated as functions
• fixed bug with nested blocks inside of a mixin printing the name of the mixin
• added the ability to specify import directory for @import
• the correct import directory is figured out automatically when you compile from file path
• fixed bug with @import and comments in imported file

• setting variables to themselves in equations works how you expect
• parentheses are supported in arithmetic
• all variables and arithmetic do lazy evaluation, variables are set to the equation and not the value
• code no longer throws php notices

• issue with comments and whitespace on head of document fixed

• Performance enhancements (50% faster compile for average case)
• Accepts more native css properties and values (still some trouble with more advanced css3 stuff)
• Better string support in general
• Comments will no longer be interpreted from within strings

• New @import parsing, supports media
• Repeated properties are all written instead of overwriting each other
• Support for additional css properties and values that were left out
• New comment parsing prevents comments inside of strings from being removed
• Added a static compile on demand function to lessc
• Updated command line utility significantly
• Fixed color rendering bug for small rgb values

• Initial release