COMslicer helps to develop reliable COM components and ActiveX controls. It traces all run time calls to selected objects of in-process or out-of-process COM components. COMslicer displays values of input and output parameters for each method or property called by clients. It also provides detailed information about such events as creation and destroying of COM objects. Debugging and testing of COM components with COMslicer facilitates resolving of problems that cannot be traced in a static debugger environment. In a real word run time environment COM components can be exploited in a way that is unexpected for developers. Observing the behavior of COM objects allows to realize sources of errors or potential problems. COMslicer can trace COM components written in VC++, VB or VJ++ languages. A developer's efforts are not needed to use COMslicer - it does not require inserting any additional code into the component's source code or building a debug version of COM component. COMslicer uses only type library information that is usually automatically included into DLL/EXE that contains COM component. Main features of COMslicer: - COMslicer displays all calls made by client(s) to selected COM objects in real time; - COMslicer's Explorer-like user interface allows browsing of displayed trace; - COMslicer keeps track of COM objects' referencing and creates report about used interfaces after objects are destroyed; - COMslicer can trace COM components written in any language with no efforts required from the developer.