Arduino and Processing - .INO and .PDE - very confusing.

I just installed Processing and find it uses .PDE files just like Arduino. Couldn’t they think up another extension (such as .PRO)?
So how do I know what “Sketchbook” sub directory a .PDE file should be saved? Also there is no such thing as a “Sketchbook” subdirectory as described in all the Arduino and Processing help files. On my computer all new .PDE files are saved into the /Arduino subdirectory of my documents directory. I guess I should save new Processing .PDE files into the /Processing sub of my documents (if I only knew which are which).

Installation is so unprofessional. When I upgrade to a new revision there is no installation startup.exe - all the old files and shortcuts must be manually deleted and new shortcuts re-created.

Very confusing support software for excellent hardware. Just wanted to get this off my chest.

warren631:
Couldn't they think up another extension (such as .PRO)?

Who is they?

Processing came first. PDE was probably short for "Prodcessing iDE".

warren631:
So how do I know what "Sketchbook" sub directory a .PDE file should be saved?

Look in preferences.

warren631:
Installation is so unprofessional. When I upgrade to a new revision there is no installation startup.exe - all the old files and shortcuts must be manually deleted and new shortcuts re-created.

One could argue this is a feature. It allows for running concurrent IDE versions which have different core files in them. It also means you as the user sees where all of the files are instead of hidden by an installer.

Of course, it depends on your operating system.