This started off as an annoyance that I could not fix the bibliography engine in TeXShop in the same way that I can with the TeX engine. For example
% !TEX TS-program = pdflatex
overrides the default to ensure that the document is always compiled with pdflatex. The original post on TeX.sx can be found here.
This script was conceived to allow the selection of a bibliography engine in a similar way. At present it handles biber and BibTeX (all lower case, since it uses a regular expression to extract the command to use)
% !BIB TS-program = bibtex
% !BIB TS-program = biber
By telling your TeX shell to use this script as your bibliography processor, the script checks for a line like the above to determine the engine to use. If no line is given, it defaults to BibTeX.
Before working with this, please ping me.