My original intent was to post as many of Aquinas's Latin texts as I could get in digital form. But the phenomenal growth of the internet in recent years, including all things Thomistic, has made it clear to me that others would inevitably do this same thing, and do it in a far superior way. This has now come to pass, making this page useful only as a gateway to other, superior sites.
Currently, the most comprehensive and impressive sites are those of Mathew Caughron and Enrique Alarcón, each of whom has posted all of Aquinas's Latin texts. Alarcón's page is an incredible tool for searching Aquinas's texts, but the interested reader should consult both pages.
Both Caughron and Alarcón have taken this material largely from Busa's Opera Omnia, although Alarcón uses other sources as well. The sophistication of Alarcón's search engine makes the old Busa CD-ROM now obsolete, so far as I can tell, but so far as I know it is still available, from Frommann-Holzboog.
The Busa edition, and hence the above web sites, simply reprint earlier editions, and in many cases do not offer the most up-to-date Leonine versions of texts. Readers concerned about such matters should know about the following.
First, and most importantly, the Bibliotheque Nationale de France has put many of the Leonine volumes on-line. The following can be downloaded absolutely free of charge:
Second, the Polish Province of the Dominican Order has put a number of Leonine editions on the internet, including
Third, Carlo Leget has kindly made available to me his edition of two sermons that will some day be published as part of the Leonine edition.
Finally, here are some miscellaneous items that might be useful.