We're looking to show a revision history between two text entries, ideally using semantic html with demarcating edits tags:
So for example:
Stack Overflow is a question site for professional and enthusiast programmers
Stack Overflow is a question site for enthusiast programmers like you
Stack Overflow is a question site for <del>professional and</del> enthusiast programmers <ins>like you</ins>
A simple word by word diff is likely to run into challenges as soon as the string is resumed if it's been replaced with more than one word at a time.
The diff doesn't necessarily need to markup the final product, but even just getting a tokenized list of revisions would be really helpful, perhaps by leveraging something like git.