FictionBook (.fb2) — open XML-based e-book format Office Open XML — .docx (XML-based standard for office documents) OpenDocument — .odt (XML-based standard for office documents) OpenOffice.org XML — .sxw (open, XML-based format for office documents) OXPS — Open XML Paper Specification (Windows 8.1 and above, older version is XPS used in Windows 7) PalmDoc — Common[citation needed] Handheld document format Plucker — Handheld navigable widely used[citation needed] document standard .pages for Pages PDF — Open standard for document exchange. ISO standards include PDF/X (eXchange), PDF/A (Archive), PDF/E (Engineering), ISO 32000 (PDF), PDF/UA (Accessibility) and PDF/VT (Variable data and transactional printing). PDF is readable on almost every platform with free or open source readers.