SnapGene Viewer is software that allows molecular biologists to create, browse, and share richly annotated DNA sequence files up to 1 GB in length. Features include visualize: Create a DNA sequence file by either entering a sequence, or importing a record from GenBank, or opening an annotated sequence stored in one of many common file formats. Browse or print a DNA sequence and its annotations using customizable Map, Sequence, Enzymes, Features, Primers, and History views. Search a DNA sequence to match either a DNA query, or a protein translation, or an annotation. View and edit DNA sequence traces. Annotate: automatically annotate common features, or manually annotate coding sequences and other features, design and annotate primers for PCR, sequencing, or mutagenesis, and identify open reading frames (ORFs) with a single mouse click. Share: export a plasmid map as an image, or export an annotated DNA sequence to GenBank format and freely share data with your colleagues or customers using the universally accessible SnapGene format.