What programming languages are influenced by PHP? It really is a leaf node. This is not intrinsically a criticism. PHP arguably got a lot of libraries created that copies the way it did HTML templating (and I mean the core PHP here, not subsequent template libraries), but that probably wouldn't show here.

The flip side of this, incidentally, would be Haskell. Still pretty unusual to encounter in the wild, but it has influenced a lot of languages, and will continue to do so, possibly without ever being a top-tier success itself.

It looks like the size of the node foo is determined by how many languages were influenced by foo, where "influence" does not include cautionary avoidance of foo's choices.

The size of the nodes are based on how much influence a language's design has had on later languages. PHP may have a lot of market share, but not a lot of languages have copied its features.

A better title for the page would be the one from the linked blog post, "How Programming Languages Influenced Each Other", at http://exploringdata.github.io/info/programming-languages-in....

Once you have PHP you don't need any other languages.

C# is a small node. it influenced java a lot.