grass super viewer

  There was a posting about a grass compatible
  super-viewer (I recall there was a comercial MS
  version and PD unix version, but I cannot find
  any address or reference to it..
  ) can some one please provide a pointer?

   I need source for a simple X based interactive display,
  which will allow user to select layers displayed,
  zoom, pan, add labels and ROIs and accept grass
  format of raster and vector data...

   Peter pom@llnl.gov