Spidey is an mRNA-to-genomic alignment program. For a complete description of how Spidey works, visit http://www.ncbi.nlm.nih.gov/spidey/spideydoc.html. This is just repackaging of the ready binary for x86 and will not run on x86_64. It will probably work just fine on a Slackware multilib box, but we do not support that ;). If you want to build spidey from source, you should download and compile the NCBI toolkit. For more information: http://www.ncbi.nlm.nih.gov/spidey/spideysource.html