Works perfectly fast with a lot of huge files

I had to rename a few thousand files from JJJJ_MM_DD to JJJJ-MM-DD and it worked perfectly fast and did not pose any problems whatsoever.
The reason I give it only four stars is the help and introduction for the advanced script language - there is not much to read there and you basically won’t get it unless you are a seasoned programmer. With a little more help I think I could maybe use the scripts too.

god_is_in_the_tv about Name Mangler 3, v3.3.2