JViz.Rna —a Java tool for RNA secondary structure visualization. Many tools have been developed for visualization of RNA secondary structures using a variety of techniques and output formats. However, each tool is typically limited to one or two of the visualization models discussed in this paper, supports only a single file format, and is tied to a specific platform. In order for structure prediction researchers to better understand the results of their algorithms and to enable life science researchers to interpret RNA structure easily, it is helpful to provide them with a flexible and powerful tool. jViz.Rna is a multiplatform visualization tool capable of displaying RNA secondary structures encoded in a variety of file formats. The same structure can be viewed using any of the models supported, including linked graph, circle graph, dot plot, and classical structure. Also, the output is dynamic and can easily be further manipulated by the user. In addition, any of the drawings produced can be saved in either the EPS or PNG file formats enabling easy usage in publications and presentations.