Joe has posted the German lyrics. Here are Austrian lyrics of this Salsburg carol. No composer is listed; it seems to be traditional.

Lyr. Add: STILL, STILL, STILL
(Salsburg dialect, '1819')

1.
Still, still, still,
Weil's Kindlein schlafen will!
Maria tut es niedersingen
Ihre keusche Burst darbingen
Still, still, still,
Weil Kindlein schlafen will.
2.
Schlaff, Schlaff, schlaf,
Mein liabes Kindlein, schlaf!
Die engel tuan scho musizieren
Bei dem Kindlein jubilieren,
Schlaf, schlaf, schlaf,
Mein liabes Kindlein, schlaf!

www.hymnsandcarolsofchristmas.com/Hymns_and_Carols/still_still_still_austrian.htm
With midi and Noteworthy Composer
Still still still Austrian

Lyr. Add: STILL, STILL, STILL (English)
(English, Salzburg 1819)

1.
Still, still, still
One can hear the falling snow.
For all is hushed,
The world is sleeping,
Holy Star its vigil keeping.
Still, still, still,
One can hear the falling snow.
2.
Sleep, sleep, sleep,
'Tis the eve of our Saviour's birth.
The night is peaceful all around you,
Close your eyes,
Let sleep surround you.
Sleep, sleep, sleep
'Tis the eve of our Saviour's birth.
3.
Dream, dream, dream
Of the joyous day to come.
While guardian angels without number

Watch you as you sweetly slumber.
Dream, dream, dream,
Of the joyous day to come.

http://www.cvc.org/christmas/still.htm
Excellent midi.
Still still still

Lyr. Add: HUSH HUSH HUSH
(Still, still, still; Salzburg)

1.
Hush, hush, hush!
Behold the wondrous light!
Who will ap-pear? The Christ-child dear,
For this, you know, is Holy night.
For this, you know, is Holy night.
2.
Hark, Hark, hark!
He's knocking at the door:
Hear his bell ring; for joy we sing:
Come quick, for we can wait no more.
Come quick, for we can wait no more.
3.
Yes, yes, yes,
We love thee one and all;
With gifts so bright this Christmas night,
Dear Jesus, bless us, great and small.
Dear Jesus, bless us, great and small.
4.
Thanks, thanks, thanks,
O Child, we love so well,
We children here pray, Savior dear,
Thou in our heart alone wilt dwell.
Thou in our heart alone will dwell.

Trans., F. W. Herzberer, O. Hartwig, ed., "Wartburg Hymnal," Wartburg Publishing House, Chicago, 1918.
http://www.hymnsandcarolsofchristmas.com/Hymns_and_Carols/hush_hush_hush_.htm
Hush hush hush

The text in the post by Joe Offer is cited as 'after üß (Seuss) is a website I have lost (not the modern children's Dr. Seuss).

There are choral arrangements by John Rutter, Norman Luboff, and Kevin Howlett (Sibelius Sheet music).

There is another carol called "Still, still, still!," German, which I will post later.