I have opened an old app that holds Thomas Tempelmann’s TTsDiff class dated back in 2008. I have searched both Thomas Tempelmann’s web site and Google, but it seems to have disappeared.
Is TTsDiff still being updated?
Nope. But the latest one is from 2011, not 2008: https://www.tempel.org/ftp/pub/REALbasic/TTsDiff.rbp.zip
Found here: Thomas Tempelmann's REALbasic tips & demos (fairly outdated)