ACT:
http://www.sanger.ac.uk/resources/software/act/

WebACT:
provides a database of sequence comparisons between 
all publicly available prokaryotic genome sequences, 
allowing the on-line visualisation of comparisons 
between up to five genomic sequences, 
using the Artemis Comparison Tool (ACT) developed by the Sanger Institute:
http://www.webact.org/WebACT/home