PHP On Pie is a PHP framework that combines the best ideas from PHP projects like Drupal, CodeIgniter, Kohana, and ZendFramework. It has very few core concepts: classes, models, events, slots, and tools. It lets you repackage completed apps into plugins that you or others can use later. Its smart database classes allow you to implement vertical and horizontal partitioning (sharding) easily to handle millions of users.
Comments script with pagination adds comments to a website, paginating them without affecting the rest of the page content or the page URL. It can be used with multiple pages of a site, whatever the type of the page URL (modified or not with mod-rewrite). It can be set to allow only logged-in users to add comments, and has many other settings and Admin management.