Don't just mention the Ubuntu package.
Also set the executable bit for this script. We need Bash (and not a
generic POSIX shell) because of the process substitution:
<(...)
feeding the while loop.
#!/bin/bash
#
-# W. Trevor King, 2009. Released into the public domain.
+# W. Trevor King, 2009-2013. Released into the public domain.
#
# Monitor an unfolding data directory and output a small png of the most
# recent unfolding curve
# usage: monfold <unfold_dir>
# e.g. : monfold ~/rsrch/data/unfold/20090331
#
-# Requires the inotify-tools package if you're running Ubuntu
+# Requires the inotify-tools package:
+# https://github.com/rvoicilas/inotify-tools/wiki
#
# Running something along the lines of
# qiv --watch $OUTFILE # run qiv tracing the image file