diff_match_patch

The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text.

https://cdnjs.webstatic.cn/ajax/libs/diff_match_patch/20121119/diff_match_patch.js
https://cdnjs.webstatic.cn/ajax/libs/diff_match_patch/20121119/diff_match_patch_uncompressed.js