On Developer.com today there's a new post listing ten experimental projects that are "pushing the envelope" in the PHP languages:
As the saying goes, "Just because you can do something doesn't mean you should." But in the world of programming, stretching boundaries is just part of the fun. The PHP community has never been one to shy away from bending their favorite language more ways than a shopping mall pretzel, and as the ten wild projects introduced in this article indicate, the fervor for experimentation is as strong as ever!
Here's their list of the ten projects they see as trying to stretch the language to its limits: