
Configuration Files
- Breaking Change: Removed the ability to use JavaScript as a configuration file format (more info)
 - Added the ability to use JavaScript-style comments in configuration files.
 - Added support for 
.eslintignorefiles - Allow configuration files to have any extension and assume they contain JSON
 
Formatters
- Breaking Change: Switched to using stylish format as the default for ESLint (more info)
 - Merged stylish formatter into the main repository
 - Added the rule ID to all formatter output to more easily identify which rule is causing a warning
 
Core
- Added the ability to traverse comment nodes in rules
 - Ignore shebangs in JavaScript files so ESLint can validate all Node.js files
 
Rules
- Breaking Change: 
unnecessary-strictrule was renamed tono-extra-strict no-emptynow disallows emptycatchblocks when afinallyblock is presentno-unused-varswas incorrectly reporting function expressions weren’t used when method calls were made on them - this was fixedbrace-stylewas incorrectly reporting a violation when anifstatement conditional spanned multiple lines - this was fixed
Documentation
- Lots of documentation updates and fixes
 - Setup eslint.org as the new home for documentation
 
Breaking Changes
The complete list of breaking changes are as follows:
- Removed the ability to use JavaScript as a configuration file format
 - Switched to using stylish format as the default
 unnecessary-strictrule was renamed tono-extra-strict
Complete Changelog
The following is the complete list of changes in this version:
- Config: Allow comments in JSON configuration files (fixes [#492](https://github.com/eslint/eslint/issues/492)) (Nicholas C. Zakas)
 - Bug: max-len fix to report correct line number (fixes #552) (Nicholas C. Zakas)
 - Build: Use browserify to create browser-ready ESLint (fixes #119) (Nicholas C. Zakas)
 - Docs: Ensure all rules have entry on top-level rules index page (Nicholas C. Zakas)
 - Docs: Add docs for no-fallthrough rule (Nicholas C. Zakas)
 - Update README.md (Peter deHaan)
 - Update README.md (Peter deHaan)
 - Update package.json (Peter deHaan)
 - Docs: Added documentation for semi rule (Nicholas C. Zakas)
 - Build: Reset branch coverage target (Nicholas C. Zakas)
 - Update build system to generate eslint.org during release (Nicholas C. Zakas)
 - Updated setup doc (Nicholas C. Zakas)
 - Fix #525 & #528 (Mangled Deutz)
 - Improve no-negated-in-lhs description (David Bruant)
 - Fixing typo (David Bruant)
 - Update no-new.md (Tamas Fodor)
 - Update no-extra-semi.md (Tamas Fodor)
 - Fixing broken links in documentation (Ilya Volodin)
 - Update about page (Nicholas C. Zakas)
 - Site generation build step and documentation updates to support it (fixes #478) (Nicholas C. Zakas)
 - Change message for brace-style rule (fixes #490) (Nicholas C. Zakas)
 - Add question about ES6 support to FAQ (fixes #530) (Nicholas C. Zakas)
 - Set unlimited number of listeners for event emitter (fixes #524) (Nicholas C. Zakas)
 - Add support for comment events (fixes #531) Add :after events for comments (Nicholas C. Zakas)
 - Add :after events for comments (Nicholas C. Zakas)
 - Allow config files to have any name (fixes #486). (Aparajita Fishman)
 - List available formatters (fixes #533). (Aparajita Fishman)
 - Add support for comment events (fixes #531) (Nicholas C. Zakas)
 - Add Stylish formatter and make it default. Fixes #517 (Sindre Sorhus)
 - Fix missing code exit (Mangled Deutz)
 - Added unit test for calling Config.getConfig with no arguments. (Aparajita Fishman)
 - Typo (Mangled Deutz)
 - Fixed docs typo (Nicholas C. Zakas)
 - Mark functions as used when any method is called on them (Nicholas C. Zakas)
 - Fixed: Config.getConfig is called either with a file path or with no args (fixes #520) (Aparajita Fishman)
 - Fix minor bug in no-empty rule (Nicholas C. Zakas)
 - add more info for failure messages (Nicholas C. Zakas)
 - Add ruleId to all formatters output (fixes #472) (Nicholas C. Zakas)
 - Remove unused code (Nicholas C. Zakas)
 - Correctly handle case with both finally and catch in no-empty (Nicholas C. Zakas)
 - Update documentation for no-unused-vars (Nicholas C. Zakas)
 - Ensure that bound function expressions are reported as being used (fixes #510) (Nicholas C. Zakas)
 - Allow empty catch/finally blocks (fixes #514) and update documentation (fixes #513) (Nicholas C. Zakas)
 - Updated contribution guidelines (Nicholas C. Zakas)
 - Add default setting for no-cond-assign (Nicholas C. Zakas)
 - Add build step to check rule consistency (Nicholas C. Zakas)
 - update docs: explicit cli args are exempt from eslintignore exclusions (Michael Ficarra)
 - fixes #505: no-cond-assign should ignore doubly parenthesised tests (Michael Ficarra)
 - Renamed unnecessary-strict to no-extra-strict (Nicholas C. Zakas)
 - Fixed missing documentation links (Nicholas C. Zakas)
 - Add build task to check for missing docs and tests for rules (Nicholas C. Zakas)
 - Slight reorganization of rule groups (Nicholas C. Zakas)
 - Added one-var and sorted some rules (Nicholas C. Zakas)
 - Updated Travis badge for new location (Nicholas C. Zakas)
 - fixes #494: allow shebangs in processed JS files (Michael Ficarra)
 - fixes #496: lint ignored files when explicitly specified via the CLI (Michael Ficarra)
 - More tests (Ilya Volodin)
 - Upgrade Istanbul (Ilya Volodin)
 - fixes #495: holey arrays cause no-comma-dangle rule to throw (Michael Ficarra)
 - Documentation and minor changes (Ilya Volodin)
 - Adding missing package registration (Ilya Volodin)
 - Adding support for .eslintignore and .jshintignore (Closes #484) (Ilya Volodin)
 - fixes #482: brace-style bug with multiline conditions (Michael Ficarra)
 - Switching Travis to use ESLint (Closes #462) (Ilya Volodin)
 

