The zlib-flate program is part of the qpdf package.
The zlib-flate program reads from standard input and writes to
standard output either compressing or uncompressing its input using raw
zlib compression. It can be used to uncompress or compress raw PDF
streams or other data that is compressed with raw zlib compression.
This program is provided primarily as a debugging tool, though it
could be used for other purposes, such as being called from a script
that creates simple PDF files.
This program should not be used as a general purpose compression
tool. Use something like gzip(1) instead.
For details about qpdf, please see the qpdf manual, which can be found
in /usr/local/share/doc/qpdf/qpdf-manual.html or /usr/local/share/doc/qpdf/qpdf-manual.pdf.