Where can I download Filemerge - the app for comparing two tools and merging them? I would like to install Filemerge, but can't find where to go to download it. Where can I download it?
FileMerge is part of Xcode 4.x by Apple which you can download from the Mac App Store.
The following is taken from the description:

Xcode is now distributed as an application, rather than as an installer. This change enables Xcode to be updated directly from the Mac App Store.

Includes SDKs for Mac OS X 10.7 Lion and iOS 5
New code signing workflow supports signing OS X apps with Developer ID
Adds installation of command-line tools to the Downloads preference pane
Open Developer Tool menu launches Instruments, FileMerge, and other tools
ARC migration tool converts both retain/release and garbage collected code
Additional bug fixes and stability improvements


But FileMerge.app is now embedded inside the Xcode.app package and is not easily accessible as a standalone tool... Unless you do this:

Browse to /Applications/Xcode.app
Right-click -&gt; Show package contents
Contents -&gt; Applications
Right-click FileMerge.app -&gt; Make Alias -&gt; Enter password
Copy the Alias to somewhere, like /Applications
Delete the original Alias

Now you can use as a standalone tool, as before!