Harm Fesefeldt did these arrangements from scores read into MIDI format by his own program. He provides these files on his website as demonstrations of his program.
When I contacted Harm, he confirmed that the programs and all the musical compositions on his website are copyright by him, released under the GNU 2.0 license.
Please see the statement about the license on his website.
Other Credits
All String soundfonts (Violin, Viola, Cello) : Nando Florestan