In June 2005, after some criticism from KHTML developers over lack of access to change logs, Apple moved the development source code and bug tracking of WebCore and JavaScriptCore to OpenDarwin.org. WebKit itself was also released as open source. The source code for non-renderer aspects of the browser, such as its GUI elements, remains proprietary.
The final stable version of Safari 2, Safari 2.0.4, was released on January 10, 2006 for Mac OS X. It was only available as part of Mac OS X Update 10.4.4. This version addresses layout and CPU usage issues, among others.[15] Safari 2.0.4 was the last version to be released exclusively on Mac OS X until version 6 in 2012.