GTK:
	Works with C, C++, Python, etc.
	Works on most platforms (Windows, Mac, Linux, etc)
	Usually assembled by XML file, or directly in C/C++/Python/whatever
	Layout is by a resizable grid
	Open-source, can sell it without license

QT:
	Works with C, C++, Python, etc.
	Works on most platforms (Windows, Mac, Linux, etc)
	Usually assembled by drag and drop
	Free for students and open-source, but costs money for commercial use

Tk (Tkinter):
	Works with scripting languages (Python, Bash, etc)
	UI layout is usually from code
	I think it's simpler to learn than the others
	Open-source, can sell it without a license

Curses:
	Operates in the command line, so you can run it on isoptera in a command prompt
	Works with C/C++/Python/etc
	Tends to be a little more of a headache to get everything working right
	Open-source, can sell it without a license

Platform-specific GUI:
	Platform-specific
		Only runs on one platform
		Allows you to use all features of that platform
	No licensing restrictions for using it
	Difficulty of use varies by platform
	Maybe you need an apple developer license for apple?  I don't know