The original hashcash package includes a program called sha1-hashcash.
However, since Debian already includes sha1sum in the coreutils program,
sha1-hashcash is not distributed in this Debian package.

This distribution also includes Kyle Hasselbacher's hashcash-sendmail and
hashcash-request scripts, which can be found in the examples directory.  The
hashcash-sendmail script can be used to integrate hashcash into MUAs that do
not support hashcash natively, such as mutt.  hashcash-request can be used to
pre-request hashcash tokens for future use.  The current version of both
scripts are considered ALPHA quality.  Use at your own risk.

For users with multi-processor machines or clusters, the examples directory
also includes a wrapper script, hashfork.py, written in Python, to start
multiple instances of Hashcash.  Running n processes on a machine (with at
least n processes) will roughly divide the average time required to generate a
stamp by n.  Note that since Hashcash is numeric-intensive, one will not be
able to get better performance out of a single hyperthreaded processor using
this technique.
