Find statistically significant patterns in sequences

 Smile determines sequence motifs on the basis of a set of DNA, RNA or
 protein sequences.
  * No hard limit on the number of combinations of motifs to describe
    subsets of sequences.
  * The sequence alphabet may be specified.
  * The use of wildcards is supported.
  * Better determination of significance of motifs by simulation.
  * Introduction of a set of sequences with negative controls
    that should not match automatically determined motifs.