Keytweaker is a small machine language memory-resident program that is used to remap keyboard keys. I use is to remap the Caps Lock key to "Disable", but I could use it to make the Caps Lock act as a hotkey if I had a pressing need to do so. Now that MS has come up with Power Toys and one of the Toys is a key mapper, I can probably get rid of Keytweaker since it is an old, old program - I have been using it for almost 20 years.
CutePDF is an inexpensive program for manipulating PDF files (combining, editing, etc.) Again,. now that Word allows you to save as PDF or to open PDFs for editing, I could probably get rid of it, but again, I have been using it for over 10 years and I am used to it - besides, it does a lot more, since one of the functions is a form-filler, so i can fill out PDF online forms with it.
I use Belarc occasionally, just to make sure that there are no hidden "elves" that I need to handle.