There are ways to do it.
If you save the files as native Sibelius files, you can distribute them to anybody by the usual means of floppy, cd, e-mail etc. The recipient can them view them (and play them) using the free Scorch viewer from Sibelius.
Alternately, print them to .pdf files, using Adobe, fineprint or some other piece of sofware. The resultant files, which could be quite big, can then be distributed as normal, and viewed by the free Acrobat viewer (like looking at pages in a book. They canb also be printed, but not played.