I've found Meld pretty good for free, but I only use it for hobby stuff so I've never needed to try out the 3-way aspect. But for side-by-side folder and file d

I've found Meld pretty good for free, but I only use it for hobby stuff so I've never needed to try out the 3-way aspect. But for side-by-side folder and file diffs I've found it decent enough relative to Araxis. And, like Araxis, both sides are editable, something not all diff tools get right. So you can experiment, and/or set up a blank diff and paste stuff in to see what you get. Main problem I've had is that it's slow for large files. I think it's written in Python. An outsize annoyance (which is objectively just a minor UX nit) is that the diff setup dialog displays names only, not full paths. Which is silly, because a very common use case for diff tools is diffing two files that have the same name, so I notice this on about 75% of uses.