JavaScript and PHP are probably the 2 most unfortunately successful web languages. Things would've been very different if TCL was the language in Netscape and mod_tcl was shipped with Apache and part of the standard install for web hosts.
I also suggest both languages have evolved quite a bit since. Between these, though, I think modern JS has had the most impact. This can mostly be attributed to the node community, with a great deal of insights from ruby.
Things like async patterns and quality package management have changed our standards for what we expect out of modern languages, despite the coerson based parlor tricks chuckled at by those who don't use the language.
PHP, on the other hand, is still a templating language that lives and dies in a request response cycle.