I"m telling my age.

I wrote the equivalent of "Hello world" first in 1978 using Fortran on the MTS operation system at the University of Alberta.  It probably said "Test. Test".  It wasn't until 1984 when I took a C programming course at UBC that I would have actually used the phrase "Hello World!" as my first test compile in a language.  In between those I would have done the equivalent in dBase II, Apple Basic, UCSD Pascal, Forth, and dBase III on various hardware I had my hands on including an Apple II, Apple LISA, Victor 9000, IBM PC, Apple Macintosh, Kaypro, TRS80, Osbourne 1, and an IBM XT.  Those compilers or interpreters were running various operating systems including CPM, CPM86, MSDOS, Apple DOS, and Coherent (first Linux on an IBM PC).