The ipad is really nice for annotating PDFs(and the 12 inch pro should be amazing for this, although I don't own one). I think Internet explorer allows you to a

The ipad is really nice for annotating PDFs(and the 12 inch pro should be amazing for this, although I don't own one). I think Internet explorer allows you to annotate PDFs, but don't have a Windows machine handy right now. MS OneNote allows you to annotate PDFs, and Adobe Acrobat reader has some annotation capabilities (and their paid version annotates well). I usually annotate PDFs on my mac, which is not great for reading :)