This is a really good conversion. The hyperlinking makes it so much easier to trace a proposition back to the axioms. As the original Latin title reminds us, Spinoza was aiming to apply the methods of Euclidean proof to philosophical enquiry, and this conversion makes the process much easier.
For completeness, I'll just mention some bibliographical details:
Author: Baruch [Benedict] Spinoza, 1632-1677
Title: Ethics [Ethica Ordine Geometrico Demonstrata]
Translated from the Latin by R. H. M. Elwes (1853-?]
Incidentally, are you the person who uploaded the Project Gutenberg version, Tom?