I was working similar idea, but for laws. They also change quite a lot and not very well presented online.
I halted the development after I realized how complicated can word diffs get. I would be interested about techniques that you used. I it is quite good as it is, but I noticed some common problems, such as:
1. Reusing letters from words that have nothing in common:
> fury over a [-hik-]{+n increas+}e in bus fares [1]
2. Inserting few paragraphs into one word (first paragraph) [2]
That's ok. There's enough value in elevating the awareness that these things change frequently and providing a change record for those interested in a specific article, that providing a neater/cleaner way of conveying the changes is forgiven. Anyone can figure out how to read the diffs once they sit down to do it, and it still requires a human to interpret the value of changes. A single word can simply be a correction or it can be a complete reversal.
If a better UI is developed later on, it can be retrofitted.
If a better UI is developed later on, it can be retrofitted.