The three catechisms shown on this page — the Roman Catechism of Trent, the catechism of St. Pius X, and the Catechism of the Catholic Church of 1992 — all belong to the Church's authoritative catechetical tradition, each in its own historical and pastoral setting.
The Latin text of the Roman Catechism, published in 1566, is ancient and may be freely studied. The English translation by John A. McHugh, O.P. and Charles J. Callan, O.P. (1923) is in the public domain in the United States, and that is the edition we draw from here, chapter by chapter.
I hold the Church's tradition in deep esteem. I read the older catechisms with gratitude, and I receive today's Catechism with the same love. Nothing on this page stands against more recent catechisms; the editorial rule is simple: reproduce only when the source is clean and licence, authorisation or public domain is verified.
For the Catechism of 1992 you find the full text on the Vatican site, and printed copies through trusted Catholic publishers. For the Catechism of St. Pius X we are preparing a verifiable English text from the Italian original.