I believe it's relatively recent. I've heard second-hand from better men than me that they are dropping a lot of legacy things. As far as I can tell, the HP is

I believe it's relatively recent. I've heard second-hand from better men than me that they are dropping a lot of legacy things. As far as I can tell, the HP is running X11R5. It doesn't do -version, the man page is for R5 and the binary is dated "Oct 27 1997" ... so yeah, 20 years ago. It's honestly a reasonable thing to break.