This is version 3.0.

* Changes since version 2.5 (no versions between 2.5 and 3.0)
  + NEW CONCEPT: "tag methods".
    Tag methods replace fallbacks as the meta-mechanism for extending the
    semantics of Lua. Whereas fallbacks had a global nature, tag methods
    work on objects having the same tag (e.g., groups of tables).
    Existing code that uses fallbacks should work without change.
  + new, general syntax for constructors {[exp] = exp, ... }.
  + support for handling variable number of arguments in functions (varargs).
  + support for conditional compilation ($if ... $else ... $end).
  + cleaner semantics in API simplifies host code.
  + better support for writing libraries (auxlib.h).
  + better type checking and error messages in the standard library.
  + luac can now also undump.

* Changes since version 2.4
  + io and string libraries are now based on pattern matching;
    the old libraries are still available for compatibility
  + dofile and dostring can now return values (via return statement)
  + better support for 16- and 64-bit machines
  + expanded documentation, with more examples

* Changes since version 2.2
  + external compiler creates portable binary files that can be loaded faster
  + interface for debugging and profiling
  + new "getglobal" fallback
  + new functions for handling references to Lua objects
  + new functions in standard lib
  + only one copy of each string is stored
  + expanded documentation, with more examples

* Changes since version 2.1
  + functions now may be declared with any "lvalue" as a name
  + garbage collection of functions
  + support for pipes

* Changes since version 1.1
  + object-oriented support
  + fallbacks
  + simplified syntax for tables
  + many internal improvements