webYourPhotos is Freeware:

FAQ:

Is it allowed to remove the backlink ?
Only in the versions before 5.4

What about the Copyright ?
The copyright headers must stay intact.
Selling the code or parts of the code or templates of this program under your own name is not allowed.

The javascript part, which makes the mouseover effect, has been writen from Mister Walter Zorn (www.walterzorn.com) So, this copyright stays at him. It ist the file wz_tooltip.js, which you will find in the templates directory. By the way, you can format this mouseover tooltip by changing the Konfiguration in the header of wz_tooltip.js.

The javascript part, to format the comments comes from Mister Kevin Roth (www.kevinroth.com). This are the files in the directory: templates/more. This copyright lays at him.