If you have SIDPlug, then you are listening to
Supremacy by Jeroen Tel
The latest version of STILView is always available here in PKZIP format:
(please, read the included README.txt file for details!)
The latest version is v2.17.
STILView (or more precisely, the STIL C++ class) is intended to be compiled with the various SIDPlays available on many platforms to provide the capability of showing STIL and BUG information along with the given SID that is currently being played in SIDPlay. It requires HVSC v2.6 (post-update #12) or later to function correctly, but it will work with earlier versions to a limited extent.
STILView is also available as a command-line version tool, which is supposed to demonstrate the current features found in STILView for SIDPlay developers, but it also makes the STILView a standalone application.
For further details on STILView, please consult the README.txt included in the source distribution!
Comments and suggestions are always welcome! If you have any, don't hesitate to write to me at LaLa_AT_C64.org!