Advise me on cross platform database query technology

I have a Linux server and application that uses PHP/MySQL to reserve seats in a venue. I want to be able to cooperate with other websites using other technologies to keep my database current. So my app would query the following possible configurations: Windows/ASPX/sqlserver Coldfusion (I have no idea what platform that uses) Other PHP/MySQL servers So that if they sell a seat or a seat cancells, my database will be updated and my site will reflect the change. My database does not have to 'automatically' update by itself, we can use an event (like a button click or something) to query the other databases for updates. Right now I only want to know if it is possible, what is involved, what kinds of technologies are involved, what kinds of security issues I would face and how to mitigate, etc. Place your bid for providing a thoughtful summary that addresses the issues I mention above, and any others. Your profile should show that you are familiar with all of these technologies. If we decide to move forward with the project, the winning bidder will have an opportunity to bid on a prrof of concept to show my clients, then on a full application.