I just posted a page explaining the O Antiphons in Esperanto, as well as a new Esperanto version of Veni veni Emmanuel with seven stanzas in the inverse order of the Antiphons (so that when singing the hymn on Christmas Eve one can, in retrospect, view the prophetic acrostic embedded in them, "ERO CRAS"). (The usual Esperanto version has only five stanzas, and not in the canonical order. The two new stanzas are my own translation.)

Incidentally, this is the 499th Esperanto hymn text page in my online hymnal, and with the addition hours later of Ho! Triumfa Pask-tagiĝo (a version of Surrexit Christus hodie) there are now an even 500 in my collection ! (as well as about 100 non-Esperanto texts, roughly half of them in English). If by chance you should need an Esperanto version of "Swing Low, Sweet Chariot" or "By Cool Siloam's Shady Rill", the index by English incipits comes in handy, and this time of year the separate Advent/Christmas/Epiphany list is helpful.

Haruo