As the author of SpecPerl, I agree that it has limitations. Only the grid manager is available and it doesn't have menus as a builtin. It started out as a simple user-freindly GUI builder that never got developed into a full visual IDE.

To clear up a possible confusion, SpecTcl (and thus SpecPerl) is an application written in Tcl/Tk, but the resulting GUI is in pure Perl/Tk--no Tcl needed.

There is an application, Guido, on Sourceforge that is supposed to be a further development on SpecTcl, but I haven't heard much from them lately. In the Tcl world, there is Visual Tcl (vtcl) which is a nice GUI builder with menus, megawidgets, etc. I have not heard of a Perl backend for it, however.

To my knowledge, there is no free GUI builder for Perl/Tk written in Perl itself.

It you have been programming in Perl/Tk for a year, it might be easier just to hand code the GUI yourself. Despite being involved with SpecPerl (which was a wonderful Tcl/Tk and Perl/Tk learning experience), I code graphical apps by hand nowadays.