[jerf]

Their github repo goes back to 1.4.0 or so around Apr 2014; their changelog goes back to 1.0.0. Go 1.0 was released March 2012. GopherJS' first commit is showing as Aug 2013. I'm not sure what GoJS' first release is but it seems likely to me it predated the Go project that really looks like "GoJS" and plausible that it predated Go 1.0 entirely.

So it looks like just one of those things.

[jjtheblunt]

I also can't find proof, but I think Go the language was previously essentially Limbo the language at Bell Labs in the Plan9 OS world, and when the team moved to Google they updated Limbo naming it Go.

It seems (from simonsarris comments) that GoJS was created in the Limbo naming era, and is itself an acronym.