Is Meld aware of the programming language when it does diffs? The problem I have with many diff tools is that they'll detect block moves without regard for things like method boundaries. Instead of showing the change as moving a method's ordering, with some changes within those methods, most diff tools treat it as just text moves and changes.
So to me, "targeted at developers" should mean something more than what Meld seems to offer (i.e., more than just syntax highlighting and regex filtering).
It's disappointing that programming language-sensitivity isn't more common. [I developed a Visual Basic compare/merge app in the early 90s that did a good job of this because it did extra work to understand the structure of the code, splitting methods and sorting them before comparing.]