Text Exchange Pro

Text Exchange Pro is an unique PHP script for running your own text link exchange system. Your users display links/ads of other users on their pages and in return their own links are displayed across the exchange network. You, as the owner of the exchange system take part of the impressions (you can choose the part, usually 30-50%) for promotion your own site or for sale. The script supports unlimited number of ad sizes and each user can have an unlimited number of ads (however administrator can limit this number).

It has a lot of advanced features, for example templates (all pages are editable in any HTML editor), real time graphical statistic, free and paid accounts and many more. List of features may be found here and fully functional Online Demo.