wxCocoaDialog is a multi-platform port of the CocoaDialog application for OS X, that allows the use of common GUI controls such as file selectors, text input, progress bars, yes/no confirmations and more with a command-line application. It is ideal for use in shell and Perl scripts (or Ruby, or Python, or... etc).
The wxWidgets port was originally created for use in the e text editor, which supports TextMate bundles and can be extended with shell scripts (through cygwin). Since it could be useful in a lot of other contexts than e, it was released to the community as open source.
These details are provided for information only. No information here is legal advice and should not be used as such.