Multiple Select Dropdown List with AJAX can be used to dynamically create multiple Select lists with data from a MySQL table. When the user chooses an option from the Select list, it calls an Ajax function which accesses a PHP file, which will return another Select dropdown according to the option selected.
Simple PHP Chat Script is an AJAX chatting system which does not require a database. It works with text files saved on the server, so it is fast and requires very few server resources. It can be included in both PHP or HTML files (in blogs, forums), but the server must run PHP. The script can easily be changed to be used in other languages, just by translating the texts in a single file. It can have one or more chat rooms. The user can add smiles in chat, and can format the text with Bold, Italic, an Underline.
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.