Credit card billing system for accessing software on Citrix applications server

We have a lot of money tied up in expensive specialized software which doesn't get used between projects. We are also a small ISP, so we already have a website. We would like to allow other professionals who do consulting (but don't have access to this kind of software) to be able to see if they want to use anything we have available, logon to our website, and have the customer's **credit card** authenticated and billed by the hour for using the software on our **Citrix server**. All software available will be charged the **same rate. ** (1) Is there an existing program we could buy and install on our server to accomplish this? (2) Any proposals involving a work-around and off-the-shelf 3rd-party software are welcomed / **preferred**. (3) If not, what else would we have to specify (ie, in the "Deliverables" block below, and/or details about our server configuration) to make sure any such new program would perform as requested above? ## Deliverables See (3) above ## Platform Windows 2000 Server, to interact with a Citrix Applications Server