Ad fontes means "to the sources." The Reformers used it as a rallying cry: stop arguing from secondhand summaries and go read what the text actually says, in the languages it was actually written in. That conviction is the whole reason the Ad Fontes app exists.
Today I'm releasing version 4.0.0. If you've been using it, you'll notice the name is now simply Ad Fontes. It began life as Ad Fontes NT, a New Testament reader. Over the last several releases it grew to cover the whole Bible, and the "NT" no longer told the truth.
What's new in 4.0.0
Full-text Library search. Search the whole Study Library by passage, title, Greek word, gloss, topic, or Strong's number, and land on the resource you need instead of scrolling for it.
Printable Study Packets. Pick a passage and Ad Fontes gathers the related material for you: textual comparisons, word studies, commentary, connections. Print it and hand it out, or keep it for your own preparation.
Gospel parallels. See how Matthew, Mark, Luke, and John tell the same events, side by side.
Confessional Connections. Passages now link to where the Book of Concord takes them up, so you can see how the Lutheran Confessions read and use the text.
Lectionaries with Sunday study packets. The One-Year and Three-Year lectionaries remain in the Study Library, now with reading links and a ready-made study packet for each Sunday.
All of these work offline in the desktop app.
What's already inside
For those meeting Ad Fontes for the first time, here is what 4.0.0 puts on your desk.
Editions to read and compare. The Berean Standard Bible is the foundational English reader, alongside the Berean Literal Bible (publisher draft), the Majority Standard Bible, Young's Literal Translation (1898), and the LXX2012 English Septuagint with the Apocrypha. For the original languages there is the Westminster Leningrad Codex (Hebrew and Aramaic), the Nestle 1904 Greek text, Robinson–Pierpont 2018, and the Boyd compilation of the Textus Receptus (2022). The Clementine Latin Vulgate rounds it out. Open them in comparison panes and read them against one another.
Old and New Testament together. Reciprocal NT/OT connections let you follow a quotation or allusion in either direction. Septuagint reading comes with interlinear glosses, morphology, search, and lemma exploration across the testaments, so you can watch a Greek word travel from the Greek Old Testament into the apostles' writing. Hebrew word analysis and lemma occurrences are there too, and Hebrew can sit beside Greek in the Old Testament study pane.
Textual evidence, honestly presented. The library holds 110 reviewed textual comparisons, each with its manuscript evidence. Where your English Bible has a footnote that says "some manuscripts add" or "other ancient authorities omit," Ad Fontes shows you what is behind that note. The aim is not to unsettle anyone. It is the opposite: when you can see the evidence for yourself, you no longer have to take anyone's word for it, including mine.
Word study and commentary. 250 Greek word studies, a 5,400-entry Greek lexicon, seven Hebrew word studies, and the historical commentaries of Lenski and Keil & Delitzsch. Any Ordinary Means commentary is clearly labelled and kept visibly separate from Scripture itself.
Who it's for
Ad Fontes is built for the serious lay reader, the Bible-study leader, and the Sunday school teacher. You don't need seminary Greek to use it. You do need a willingness to slow down and look. If you teach, the new Study Packets and lectionary pages were made with you in mind: open the passage for Sunday, print the packet, and walk into class with the sources in hand.
How to get it
On the web: go to ad-fontes.app. No account, no sign-in.
On the desktop: download it for macOS (Sonoma 14 or newer on Apple Silicon, signed and notarized) or Windows 11 (x64). The desktop app works fully offline for reading and study, and it checks for stable updates and asks before installing anything.
Already running Ad Fontes NT? Use the app's built-in updater. It keeps your installation and saved preferences, and on a Mac it avoids leaving you with a second copy after the name change.
It's free. It will stay free. The sources belong to the church, and so should the tools for reading them.
If something breaks, or a comparison or note looks wrong to you, I want to hear about it. Visit the Support page or write to me at [email protected].
And if you know a teacher, a pastor, or a friend who reads their Bible with a pencil in hand, forward this along.
Back to the sources,
Larry