Central to every development platform is its software development kit (SDK), which enables third party developers to deliver applications running on the plat- form. Such a kit can include among other things, libraries, debuggers, and hand-set emulators. Existing platforms have taken different approaches when it comes to sharing their SDK with developers. Some have chosen to restrict access as much as possible, whereas others have chosen to disclose the entire source code of their SDK and OS. Using the terminology introduced by Raymond in [12], we call bazaar an open source platform, where any third party developer can access the entire platform with no, or little, restrictions and contribute to the construction of its structure. Conversely, we call cathedral a closed platform, where most of the code is hidden from developers and an all mighty architect plans every inch of the platform's construction.