One of the unsung software heroes in law departments is its red-lining program. Microsoft Word has a red-line capability, but specialized packages have many more capabilities. For example, many law departments I have worked with have licensed DeltaView.
Given that much of the work of in-house lawyers revolves around contracts and drafting modifications to them, it becomes crucial to be able to show changes from one version to the next. It is a real tool for productivity (See my posts in the category of productivity; and Feb. 9, 2008: 27 packages for law departments.).