What's in a Name?

I get a ton of spam every day, like most people do. Yes, it's annoying, and some are just disgusting, but one thing that amuses me about some of them are the "from" names they use. Here are just a few of the "people" who have sent me messages in the past two weeks:

Forgave K. Convertible
Niggard P. Thessalonian
Gos A. Unorganized
Statistician I. Imbicilities

What program do these spammers use to come up with thse names? It's highly entertaining, whatever it is.

And the subject lines! These are real subject lines of spam messages I've received recently (uncorrected):

Also tropospheric i'd sepal purgatory
I psychic may shun suggestible
Hello irreverent that alma ambient
It's bigelow why angelfish affirmation
Hi dualism i'd baseplate sowbelly

and my favorite:

I'd fruit that midwinter leprosy

Who comes up with these things and, more importantly, who replies to them?