The "genealogical tree" looks interesting. Unfortunately the JPEG compression applied to the image makes the names of the languages illegible.

Since when Dlang is "Variant on C++" Also, they have Dark Basic but not DIV ??

Unnavigable. The image is not a map, the search expects exact year, and top links refer to papers and other items. Maybe I will wget for personal use.

"Object REXX, 1996, International" seems a bit thin for an encyclopaedia entry.

It would be nice if it redirected to REXX if it was that small: http://hopl.info/showlanguage.prx?exp=868&language=REXX

I was thrown by the coloured overrides and removal of underlines from the normal display of hyperlinks and wasn't looking at the actual entry. I've read the explanation page for all of the colours, now. (-:

That said, the real entry says "OO version of REXX".

It stops with 2004. Where there no new languages afterwards?

Certainly not. We had enough languages by then and nobody thought a new one would add any more value.

It is also when the relevant xkcd came out, spurring people to stop creating languages.