It's Perl/Tk, "compiled" (packed into an .exe wrapper actually) with ActiveState's PerlApp. Most of my applications are Perl/Tk or VB6+Perl. cchargin's MDLOps is also Perl/Tk.
KSE doesn't need anything other than permissions to unpack itself to a temp directory, the ability to read/write to the registry (administrator permissions on Vista), and obviously the ability to read/write to your savegames.
KotOR Tool, written in VB.NET needs .NET Framework installed.
Stoffe's utilities are written in Delphi (Object Pascal).
Torlack's NWNSSCOMP.exe is written in Visual C++.
IIRC, only JDNoa's DeNCS utility requires Java as far as KotOR modding utilities are concerned.