Sourcecode stolen from others.  Why stolen?

According to the MI and MPAA it is illegal to look a screen when others are watching it.
There is no difference if you watch a screen now or in 100 years.
If there would be any difference there aint such a thing like radio astronomy.

So there is no difference if you watch a copy of a film or watch it right on the screen.

Following the weird thoughts of the MI or MPAA using Public Domain software thus must be stealing, too.
As I am a honest person, I never lie and use this opportunity to tell the truth about me:
I am a thief, because I have two eyes which are able to watch films.
This is due to the fact that there is no infinite light speed, and photons must be copied
and transcoded by my biologigal receptors and stored in my brain (the MI/MPAA says, this is theft).

Back to the problem:

According to the web pages at http://www.fourmilab.ch/md5/ md5.h and md5.c is Public Domain:

The MD5 algorithm was developed by Ron Rivest. The public domain C language implementation used in this program was written by Colin Plumb in 1993.