Wx, Prima, Tkx. As mentioned earlier, GTK, QT. Some people call DHTML a GUI. WxGlade can generate Perl WX code for you. GUI Loft for Win32::GUI. SpecTCL for Perl TK or TKX I dont remember. GuiBuilder is more modern decendent of SPecTCL, it makes Perl TK and TKX code. Last I checked there is nothing that will produce perl GTK code for you. Glade doesn't do it.
But it is not difficult to translate the generated C code to Gtk2.pm. The APIs are similar.
The APIs are identical only the calling convention is different, but there is also no point in doing the translation yourself, it misses the point of using Glade, the idea behind Glade is for it to generate code for you
Glade::PerlGenerate glade2perl - Builds Gtk-Perl sources from a Glade file
glade2perl-2 - Builds Gtk2-Perl sources from a Glade-2 file
Glade2::Widget - Creates a new widget from a .glade file. It accepts the following parameters.
Gtk2::GladeXML - Create user interfaces directly from Glade XML files.
Gtk2::GladeXML::Simple - A clean object-oriented interface to Gtk2::GladeXML