[SOLVED] I am curious about non-commercial shareware license for xv

This is what I found in changelog
Quote:

extra/xv/xv-3.10a-x86_64-9.txz: Rebuilt. Moved here from the XAP series due to non-commercial use shareware license

what does it mean? Can I still use xv? I use xv to set up root window background for twm. As I remember shareware for windows is app. which can be used for some period of time then user needs to register and pay for application. Does it the same situation? Essentially on of most important point to use Linux is just I can avoid such shareware ****. So please someone be so kind to explain to me these issues?