And when you have any sort of text file that you cannot open with other applications, BBEdit is almost certain to be able to cope with it. Rarely a day goes by when we do not use BBEdit to check out a file or two. This means it lists all open processes on your Mac and selectively lets you quit them. With a process manager, you can quit an extension without having to restart. It's not the only utility that can do this, but it's the best.
Snitch remains a personal favorite.
The main thing it does is allow you to change file type and creator codes, as well as turning on or off various Finder attributes. What sets it apart from other similar utilities is how easily it does it. Just select Get Info for the file you want to edit and you're there. It even has popup menus of frequently used codes, so you don't have to remember them or type them. Via plug-ins, it has additional features, such as the ability to make invisible files within a folder visible.