The Weekly Squeak

http://lists.squeakfoundation.org/pipermail/squeak-dev/2012-September/165795.html

There is the regular Browser for looking at source code. Sure.

And then there’s the Swiss Army Knife version of the browser, the OmniBrowser, which tells you ranges of information at a glance.  The OmniBrowser is now in the trunk. Instructions for installation are available by following the link.