Yes you can use the System.Windows.Forms stuff from Perl.NET to create a GUI, but on the other hand there are other mechanisms by which you can create a .NET GUI in, say, C# and use application code written in Perl without the need for Perl.NET - windows scripting components are one way.

I don't think you need Visual studio to use Perl.NET - only the .NET Framework runtime and SDK.

An interesting alternative is PerlSharp that allows you use perl code directly from .NET - I've not tried to get this to work on windows though.

/J\