Lisphp is a Lisp dialect written in PHP. It was created to be embedded in web services or to be distributed within web applications. For that reason, it implements sandbox environment for security issues and multiple environment instances.

You can grab the latest code from the github page for the project as well as check out some of the tutorials and details about using the interpreter features like use/from, custom functions and custom macros.

My question is this: how did PHP get so many libraries, get installed on so many computers, and attract so much developer attention in the first place? [...] To summarize: Lisp is marketing itself poorly. Lisp either needs to get competitive on the ease of use and productivity front, or lose programmers to other languages.

He mentions this post from Brian Carper and this response as two places bringing up good points about Lisp and its community.

That's one of the things that PHP has going for it over Lisp - the community. PHP's community is constantly pushing, reaching out to the developers with simple tutorials and (usually) useful libraries. He makes a call to the Lisp developers out there, though:

The day will come when Lisp won't be cast aside as a quaint relic of bygone days. On that day, Lisp will be seen as equal to the big languages. And it will learn from and share with them as peers.

For site like Flickr, Wikipedia, and Facebook - all of whom deal with enormous availability problems - to have stuck with PHP, well, that means something profound. While previously I respected PHP programmers, I always felt that they must not understand much about actual computer science. They were stuck in a procedural world, and a glimpse of what "more advanced" languages could show them would "enlighten" them.

He suggests that PHP scripts, especially the "large libraries" some developers create do some very routine tasks that could be accomplished much simpler. He points out, though, that PHP does have something going for it and that, despite a difference in functionality offered, Lisp could learn something from PHP.