R is an open source statistical programming and visualization language.
R and VIVO
R provides a rich environment for data processing, visualization and analysis. Along with the R XML package for reading XML (VIVO RDF Schema is a flavor of XML) and statnet, a library for network visualization and analysis, a strong environment for development of VIVO applications can be assembled.
You can download R for Windows, Linux or Mac from http://www.r-project.org. Once R is installed, you can execute the R commands below to install the XML package and the statnet package.