[Trisquel-users] archive file formats

[adel . afzal]

Wikipedia says that the zip file format was released into the public domain.   
Does that mean that it's free?

How does zip compare to other archiving formats?  Does the answer change  
depending on the archive material size (eg 5mb, 500mb, 50gb)?

Zip seems like a good option for a workplace, partly because the big  
proprietary operating systems support it.  If you think that this reasoning  
is wrong, please tell me.

I also have to password protect the archive.  If I password my zip file, will  
Archive Manager encrypt the contents of the archive reliably (like how I  
assume GPG would)?