While not exactly a banner exchange, AutoPub allows your visitors to insert a link in your home page with a little banner to their site, until an other visitor replaces it with his. The old one goes to a gallery page. A protected admin panel allows you to modify all configuration parameters: displaying delay, banner size, fonts, colors, etc. Installation is fully automated, and there is French and English language support. It requires MySQL.
CSS Briefcase is a little program that helps you organize your CSS styles and store them for use in future projects. Just add CSS style code you tend to use in several projects, and from then on, adding the code into new projects is as easy as selecting the styles you want and clicking a button.
Contact Form is a Perl script that allows users to send you email through a Web interface. It is designed to thwart spammers by not allowing email to be sent to unknown addresses, or revealing the addresses that it knows. In addition to this, it does not contain cross site scripting vulnerabilities or allow arbitrary code to be run on the host. It provides adequate information in the headers it sends to trace spammers, can check the validity of all data before sending emails, and features a customizable interface that allows for arbitrary fields.
Contact Form Killer is a small tool to easily generate contact forms online, including form validation. You can also let your site visitors use the tool to create forms themselves. Just select what inputs you would like, and Contact Form Killer generates a complete PHP/HTML page that you can use as a full contact form for your site. Choose from 11 different inputs and decided which ones are required for users to fill in.