Generally, the interactivity provided by web applications is carried out through surfing, as a result of a server’s response at the request of a workstation. This is an essential characteristic of this type of software, although in some circumstances it turns into a functional and operative constraint. This paper solves the specific problem of a Real Estate CRM (Customer Relationship Management) by means of a web application, in which, in order to fulfill certain functional requirements, a similar desktop system interactivity is provided. To do this, the use of standard technology (PHP-MySQL) with asynchronous JavaScript and XML is provided, thus overcoming the stakeholders’ expectations to carry out two functional requirements: first, the application must be web oriented and second, it must offer desktop system interactivity.