PDF was built into OSX from the very beginning back in 2000 and I've found it very useful to save web pages etc as PDF files. It's even better if the web page can be viewed in reader mode as it strips out all the adverts and headers etc enabling you to save a really clean copy of an article as a PDF. I've been using an iPad for about four years now and that was one thing that was missing in early versions of IOS. I'm really pleased now that Apple have addressed this problem as having it built into the OS is far better than some of the poor attempts made by app developers. I found out the hard way many years ago that just book marking interesting articles etc was a bad idea as pages change and whole websites disappeared! If you use an iPad and haven't used this facility give it a go as it's very useful for sharing articles with friends.