biber

At the moment, biber (like bibtex) doesn't provide an equivalent of TeX's
-output-directory option. I think a corresponding option would simplify
processing in situations where the TeX output directory is different from
the current directory. At the moment, if one wants to specify
-output-directory in TeX, one has to set BIBINPUTS to the input directory
and call biber from the output directory. A switch like -output-directory
would cause biber to place its output files in the specified directory, and
to search the output directory for the LaTeX-generated files (.aux, .bcf,
-blx.bib) first, but the input (current) directory and BIBINPUTS for the
user-generated .bib file.