Try system_profiler SPExtensionsDataType
(though that doesn't provide any obvious means of distinguishing between Apple and non-Apple extensions).
It works. Thank you.
Under the circumstances, I'll refer ryck to System Profiler as being the more user-friendly of the two methods of calling up the info.
And thank you for that. It also works very well. I didn't even think to look into the System Profiler.
I was looking to see if I had any 'debris' laying around on my drive (thinking about the Blue Screen Blues thread) and thought I'd look into the Extensions folder at: HD/System/Extensions.
There's a lot of stuff in there that doesn't seem correct.e.g.:
LexmaskUSBMerge.kext (I don't have any Lexmark devices)
hp-Deskjet_io_enabler.kext (And a lot of other HP stuff although I've never had an HP printer)
There's also a bunch of things just titled with characters and numbers. I don't want to goof with anything accidentally that should be in the folder, but I wonder "if it's not needed, does it get in the way?"