Run own auction site like ebay with this PHP script. Members run paid or free auctions. Also supports Dutch auctions, classifieds, fixed priced items. Demo available.
Link validator tool written in PHP helps to check automatically if a page contain a link back to site. Helpful especially in link exchange or link popularity campaigns.
A content management system provides great way for starting own jokes site. Advertising opportunities include banner ads, google adwords, affiliate ads. [Commercial]
Act as a collection of private and public image galleries. Members or administrator can create public or private galleries. Public galleries are accessible to all. While read/write access for the private galleries can be restricted. [Commercial]