This release is identical to release 3.4b, except that it is based on
a later release of VisualWorks (2.5.2 instead of 2.5.1). This
incorporates various bug fixes.

To use this release, or a later release of SDML, it is necessary to
use a VisualWorks 2.5.2 object engine or above. Release 2.5.2d is
available (and recommended) on most platforms; on others, 2.5.2
should be used.