Earlier today, Apple released a beta version of Safari 4, with the version number 528.16.
As is common knowledge, Safari is based on the open-source WebKit rendering engine, which releases nightly builds. For reference, the current WebKit version is 520.1+.
Because WebKit is open source, using WebKit’s version history tracker, it’s possible to determine the following interesting information:
* The Safari-6528 branch was created on January 29th based on the state of the WebKit trunk at r40289, from January 27th.
* There have been 75 merges of code (presumably bug fixes) into the 6528 branch since then. The last of these merges was r41097 (merging r41091) on February 19.
* The release is tagged in WebKit svn as r41182, the/releases/Apple/Safari 4 Public Beta tag.
This means that the Safari 4 beta is based roughly on the state of WebKit as it was at the end of January, one month behind current development. Considering the importance of WebKit to Safari in general, and Mac OS X as a whole, a one month delay for QA purposes is probably pretty good.
Kudos to all of the people working on WebKit! Keep up the good work!
