After reading the previous person's comments, I was naturally curious regarding this developer's home page URL. It does in fact cause one to pause. However, after visiting his site, looking over what he has to say in English in his software section, (he is German), I was left with the impression that he is not a malicious hacker looking for a back door into your system. In its original meaning, a hacker was simply a person involved with coding software, and did not have a negative connotation, as it does now.
I did download and install this screensaver, but it would not work on my G4 500 Mhz DP running Tiger 10.4.11. Double-clicking the saver did NOT install it in my screensavers folder, so I had to manually install it myself. However, even then, after selecting it in the screensaver pane in System Preferences, I received the error "CouldNotLoad_ArchMisMatch". I have no idea what that means. Perhaps the developer will figure it out.
Cafe Wall Illusion
animated version of the cafe wall illusion
Version: 1.1