Metalink's ORA-600/ORA-7445 and call stack lookup tool is incredibly useful for finding reference information on various permutations of these errors. I opened the page source for this Metalink page and it is quite interesting. The entire table of error arguments and their corresponding Metalink note IDs is visible. Also we can see the code for processing call stacks, which is educational. We learn, for instance, that the tool supports gdb backtraces.
There is always a link to this tool at the bottom of my web page, http://www.ora-600.net.