Plato's work has had a lot of support/maintenance over the years, as it has been ported from the spoken word to parchment to book to e-book, and finally translated to English, which is how I assume Dan read it.

Programming languages and environments just evolve quicker than human ones. As with books, the best ideas get ported over: you can read Plato, but other than (Socrates/Plato/Aristotle), how many Greek philosophers were around whose ideas failed to survive? VisiCalc was first implemented in seventies for the Apple II, but its ideas have survived and been ported to Excel (and now Google Spreadsheets).