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> See [commit history](https://github.com/pegjs/pegjs/compare/0.3...0.4) for a full list of changes.

## v0.4 _(April 17, 2010)_

### Big Changes

* Improved IE compatibility — IE6+ is now fully supported.
* Generated parsers are now standalone (no runtime is required).
* Added example grammars for JavaScript, CSS and JSON.
* Added a benchmark suite.
* Implemented negative character classes (e.g. `[^a-z]`).
* Project moved from BitBucket to GitHub.

### Small Changes

* Code generated for the character classes is now regexp-based (= simpler and more scalable).
* Added `\uFEFF` (BOM) to the definition of whitespace in the metagrammar.
* When building a parser, left-recursive rules (both direct and indirect) are reported as errors.
* When building a parser, missing rules are reported as errors.
* Expected items in the error messages do not contain duplicates and they are sorted.
* Fixed several bugs in the example arithmetic's grammar.
* Converted `README` to GitHub Flavored Markdown and improved it.
* Added `CHANGELOG`.
* Internal code improvements.