libsequence is a C++ library designed to aid writing applications for genomics and evolutionary genetics. A large amount of the library is dedicated to the analysis of "single nucleotide polymorphism", or SNP data. The library is intended to be viewed as a "BioC++" akin to the bioperl project, although the scope of libsequence is limited in comparison. Much of the bioperl project concerns parsing the output of various bioinformatics programs, and the management of databases of biological data. perl is a good language for such things, and libsequence tries not to re-invent the wheel. Rather, the focus is on biological computation, such as the analysis of SNP data and sequence divergence, and the analysis of data generated from coalescent simulation.