Hi kafi,
A few corrections are in order:
Open source software should be free for non-commercial personal use. As I do not see any other open source software (except TM 2) that demands license.
I don't understand why you say this, because is not true.
All software have licenses, even open source.
Most open source licenses state that you don't have to pay if you credit the author and every addition you make to your version of the software is released also as open source with the same license. Most of them can be used for personal and commercial work, but some don't.
Check a few open source licenses if you think I'm being picky: http://en.wikipedia.org/wiki/List_of_software_licenses.
cheers -- jm