I have used a stand-alone linux version of blacksilk for many years. It still works!!
see these very old links
and
(https://www.flickr.com/groups/48637250@N00/discuss/72157659522986434/)
It is the easiest black and white conversion tool I have ever used. There was talk years ago about integrating it with GIMP. Does anyone know what has happened to this very useful program?
Thanks