The censor package

This package provides simple tools for creating redacted documents with
blacked-out text.  It's tools are useful both for creating documents in
a restricted environment (for redacted release in an unrestricted
environment) as well as in an unrestricted environment (for eventual
transfer and completion in the restricted environment).

As of V2.0, the ability to blackout larger blocks of text is available,
up to a whole paragraph simply, and even across paragraph boundaries.

V2.1 tries to minimize formatting discrepancies (i.e., text spacing)
between the redacted and unredacted versions of the document.

V3.0 introduces the \censorbox command (and its starred counterpart) to
allow the redaction of more than just text, including figures, tables,
etc.

V3.1 gives unrestricted use of \par in arguments to \blackout.  Also,
\xblackout introduced to give interword blacking not offered by
\blackout.

V3.2 allows control over the characteristics (depth and height) of the
censor blackout rule.  It also gives additional control on how to handle
the censoring of periods.

v4.0 overhauls the token censoring approach to incorporate tools from
the tokcycle package, to provide more flexibility when censored material
contains macros.