The bedtools utilities are a suite of tools for performing a wide range of
genomics analysis tasks.  The most widely-used of these tools enable genome
arithmetic, i.e., set theory on the genome.  For example, with bedtools one can
intersect, merge, count, complement, and shuffle genomic intervals from
multiple files in common genomic formats such as BAM, BED, GFF/GTF, and VCF.

Although each individual utility is designed to do a relatively simple task,
e.g., intersect two interval files, more sophisticated analyses can be
conducted by stringing together multiple bedtools operations on the command
line or in shell scripts.

WWW: http://bedtools.readthedocs.org/