Shared collaboration between distributed users gains more importance due to the globalization of organizations and institutions. Besides exchanging audiovisual data, sharing spreadsheets or graphics is of utmost importance, especially in scenarios for tele-working or tele-education. Although the Internet has gained more ground in our daily work, most applications nowadays are not prepared for shared collaboration, and it is expected that this non-awareness of distribution will remain persistent for most of the applications. For that, application-sharing technologies have been developed to encounter the problem sharing these kinds of applications among a set of distributed users. Two different paradigms to realize application sharing can be distinguished, namely sharing the application’s output or the application’s evolving state. In this chapter, the realization of an application-sharing service is presented, based on the latter paradigm, which is mostly suited for closed development or teaching scenarios. The requirements for the service as well as its realization are outlined, together with the lessons we learned from this realization.