Comment on Dashcode

To update dashcode, install a newer version of Xcode, Apple's development environment: http://developer.apple.com/xcode/. You have to be an Apple Developer, but signing up is free.

Once you have signed up, Xcode 3 is free here: https://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=20792