I (Matt Butcher) released an alpha-quality revision to the original Sinciput 1.0 PHP code base. This new version, 1.5 alpha 1, is transitioning from PHP 4 to PHP 5. The primary change has been from the old DOM XML package to the new DOM package. No major changes have been done to the rest of the project.
Other than making a PHP5 version available (mainly for my own purposes), no new development is happening on the PHP version. The Java version alone is under active development.