I have a setting of Ne Timeas Maria which I wrote several years ago, if that's any help.

Introit for the 4th Sunday of Advent:

Drop Down Dew From Above

My little group has done In natali Domini from the Specialnik codex.

There's a faburden setting of Conditor Alme Siderum that my choir loves to sing: it's a Mediaeval setting from England (in the Bodleian at Oxford, MS Laud. lat. 95), it's available on CPDL. (NB: There is an error in verse 5: it says "Hostis a celo perfidi", but it should be "Hostis a telo perfidi".)

The three are usually used to distinguish compositional style, liturgical purpose, and/or nationality.

Falsobordone: Italian, usually; through-composed Polyphonic psalm-tones, in the various modes, contain a recitation chord, a mediant cadence, a second recitation chord and a final cadence. They are usually published un-texted (or with a single verse of Ps. 109 as an example of pointing), and are intended to be used with the divine office and with any text.

Fauxbourdon: usually French or Burgundian. Refers to a compositional technique whereby a third voice is improvised between two composer voices, usually by singing in fourths with the upper voice.

Faburden: English. Usually refers to a practice of Cantus super librum, where alternating verses on a hymn are sung in parallel 6th chords. Refers also to primarily English compositions in a similar style. In more modern usage, it also denotes hymn settings with the tune in the Tenor, like Downland's setting of Old Hundredth.

The English term seems to be the original, which is the only one that makes sense in relation to the musical phenomenon it describes: to sing the burden (refrain) on fa (i.e., a fourth above or below): the French is a corruption of the English, the Italian, a translation of the French.

Another popular piece is Otto Goldschmidt's (1829-1907) "A tender shoot". I don't know if it's available on CPDL, but there is a published edition by Oxford University Press.

Serviam, where can I acquire that rorate score? Lovely

Except for (harmonized) mode iii chant replacing the mode iii Anglican chant in the Gloria Patri, my (Latin) Rorate caeli desuper at CPDL is musically essentially the same as my "Drop down dew from above" higher up in this thread.

Everyone loves this medieval Gaudete — that is, the Christmas carol (not the Advent Introit). You can have a different person / group of people / section of singers tackle each brief verse. You could even have the congregation (or audience) join in on the refrain each time, if you wanted to, and the refrain is short enough that you could sing it twice before every verse, with different dynamics each time. Lots of ways to vary this little gem. Great fun, in miniature!