In a previous paper the authors argued the case for incorporating ideas from
innate immunity into artificial immune systems (AISs) and presented an outline
for a conceptual framework for such systems. A number of key general properties
observed in the biological innate and adaptive immune systems were highlighted,
and how such properties might be instantiated in artificial systems was
discussed in detail. The next logical step is to take these ideas and build a
software system with which AISs with these properties can be implemented and
experimentally evaluated. This paper reports on the results of that step - the
libtissue system.