What I want to do is select a number of .STL files in "Explorer" and open them in a single operation using the file association and have them presented as a "tabbed" view  in one instance of the program. I'm not too bothered about how long it takes to open or the amount of memory used. Google found  a couple for me but they weren't very usable or didn't open from the association. I already have a tool that provides thumbnails of .STL files, it works well but I need a bit more functionality. Best regards, Dave