EP0463250: Data processing apparatus user interface and data processing apparatus with such an interface (IBM (US)) http://swpat.ffii.org/patents/txt/ep/0463/250/ Claims: 1.) Assure to open a certain window only once (to prevent conflicts) 2. to 6.) Tagging of window classes and switching between windows of same class via a keyboard; conditional window opening (checking for conflicts) 7.) Apparatus implementing 1. 8. to 14.) analogous, implementing 2. to 6. Violation programm, Python script (CAUTION: PLEASE DO NOT EXECUTE!): noconflict.py (see attachment) This program is quite big, but that's normal for GUI applications. It uses Tkinter, the standard widget set in Python. A new class, Window, is defined, derived from Toplevel. Its constructor and destructor control the contents of the global variable winopen which is 1, if, and only if, the window already exists. The function newwin() is a callback which is called, when a user requests a new window and opens it in the case that no such window exists. The last three lines of code create the root widget (a toplevel window), where a button is packed, which can be used for window creation. The script runs into an infinite loop to be aborted by Ctrl-C or closing the root window. The claims 1 and 7 are violated simultaneously, because the program implements the method and (together with and running on a normal PC) realizes the specified apparatus. CAUTION: This patent is violated by the Federal Government of the Federal Republic of Germany on it's website http://www.bundesregierung.de/, where the button "sitemap" opens just one additional window (on subsequent clicks only after closing this window). -> 2 claims violated, 1x caught Federal Government Roland Stigge