samtools

The original samtools package has been split into three separate but tightly coordinated projects: - htslib: C-library for handling high-throughput sequencing data - samtools: mpileup and other tools for handling SAM, BAM, CRAM - bcftools: calling and other tools for handling VCF, BCF

See also http://github.com/samtools/

HTSlib

HTSlib is an implementation of a unified C library for accessing common file formats, such as SAM, CRAM and VCF, used for high-throughput sequencing data, and is the core library used by samtools and bcftools. HTSlib only depends on zlib. It is known to be compatible with gcc, g++ and clang.

HTSlib implements a generalized BAM index, with file extension .csi (coordinate-sorted index). The HTSlib file reader first looks for the new index and then for the old if the new index is absent.

This project also includes the popular tabix indexer, which indexes both .tbi and .csi formats, and the bgzip compression utility.

BCFtools

This is the official development repository for BCFtools. It contains all the vcf* commands which previously lived in the htslib repository (such as vcfcheck, vcfmerge, vcfisec, etc.) and the samtools BCF calling from bcftools subdirectory of samtools.

For a full documentation, see bcftools GitHub page.

Other useful links:

File format specifications live on HTS-spec GitHub page htslib samtools tabix