Cassiopee is an index and search tool and library for bioinformatics (could be used for others but provides additional stuff usefull in sequence analysis). It is a complete rewrite of the ruby Cassiopee gem. It scan an input genomic sequence (dna/rna/protein) and search for a subsequence with exact match or allowing substitutions (Hamming distance) and/or insertion/deletions. It also support alphabet ambiguity. This program provides both a binary (Cassiopee) and a shared library.