Readseq allows the user to read & reformat biosequences

Readseq was written originally around 1989 as a component of a sequence analysis program, but when a small, simple command-line interface was added, it took on a life of its own as a conversion program for bioinformatics. It's main contribution to bioinformatics is that it takes on the job of guessing what your input biosequence data format is, and converting it to what your software knows how to handle.