The original SpecTcl only supported a single, hard coded visualization program, Xamine. While Xamine is still supported, the internal support for visualizers has been generalized to provide the ability to extend SpecTcl to use other display programs.
The Spectra, root based display program was written and abandoned before gaining much traction because the CERN/Root team abandoned QTGsi and went in a much different GUI direction. A Python/Qt based displayer using MatPltoLib is being developed and will live on top of these classes documented below.