The program Spectrogram was originally developed by Allan Peevers on SGI IRIS workstations as part of his Master Thesis at University of California, Santa Cruz in early nineties.
It was later ported to modern IRIX OS and functionally extended by Stanko Juzbasic. However, even this updated version still relies on IRIS Graphics library and Forms window toolkit, written by Mark Overmars at Royal Utrecht University, The Netherlands, which both work only with SGI hardware.
This is an attempt to bring the port one step further by replacing all IRIS GL instructions with their OpenGL closest substitutes, as well as replacing the entire windowing code with XForms (which is a substitute of aforementioned Forms to universal UNIX X Window System). This also implies that the entire user-interaction code has to be rewritten from scratch. We've come to the point of making it functional. This is still a work in progress, and can be downloaded from here.
Any suggestions are welcome.