XmVaCreateLabelGadget(3) on Linux
The text 688c1811d2cf, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A LabelGadget widget convenience creation functions. "XmVaCreateLabelGadget" "XmVaCreateManagedLabelGadget" "creation functions"