Intellisense (or any other code completion functionality) such as auto-code-completion and showing the properties and methods of an object (tdf#66185); 3.
Error checking (the IDE actually knows its symbols).
Not available in the desktop applications (tdf#73831), see development information: Collaborative Editing and Track changes.
See also GSOC 2016 project: Saving ODF XML of Change-tracking as a Sequence of Pre-defined Changes.
More comprehensive features require an eligible Office 365 subscription at a monthly fee. Variety of available service providers: Ur Berri, eqipe, New Access, Arawa, Artistanbul, Transfert Pro, Extensys, Rono-IT, Secured Store, Studio Storti,united hoster, Option Service Télécom, Aggre Cost, Webo.hosting, File Cloud, Retention Range, au, Offi Docs Partial.
Libreoffice/Collabora Online: version 2.1 released with full document support and rendering fidelity, reduced editing functionality, collaborative editing. Collaborative editing in Libre Office online version (Writer, Calc and Impress).
Simplified "sharing" of office documents in MS Word, Excel, Powerpoint via One Drive, One Drive for Business, or Share Point.
Feature inconsistencies/differences in Windows versions "MS Office 2016" sales version and the "Office 2016 for Office 365" rental version: some features are being subsequently included only in the rental version (newly added features also differ between mac OS and MS Windows) leading to inconsistencies in the feature set (see below).
Extended support (spell-check dictionaries, hyphenation patterns, thesaurus and grammar check, specialized dictionaries as extensions (, , )).
Ports for Android and i OS in development, viewer for Ubuntu Touch: Libre Office Viewer for Android is available.
The Android viewer also contains basic and experimental editing features, more information: Android port wiki, , , , ,.