The DDP Mastering Tools are written by Diplom-Tonmeister Andreas Ruge.
Andreas, after having graduated from the well known Detmold Conservatory of Music's Tonmeister program in 2001, has been working as recording producer and engineer for classical music productions in as many as 14 different countries around the world, working for such labels as BIS Records, cpo, EMI, and Sony among others. Since many years he has been part of the Marlboro Music Festival's staff, helping to maintain their large heritage of audio recordings. Andreas also holds a position as software developer in a Health IT business. He lives with his family in Southwest Germany not far from the city of Freiburg.
If you are really curious, you might want to look him up at allmusic.com to see a partial list of his work.