Apache OpenOffice

Apache OpenOffice (AOO) is an open-source office productivity software suite. It is one of the successor projects of OpenOffice.org and the designated successor of IBM Lotus Symphony. It is a close co...
Language(s): C++, Java
Operating system(s): Linux, Mac OS, Windows
License: Apache License 2.0

Calligra

Calligra Suite is a graphic art and office suite by KDE. It is available for desktop PCs, tablet computers, and smartphones. It contains applications for word processing, spreadsheets, presentation, d...
Language(s): C++ (Qt, KDE Platform)
Operating system(s): Unix, Linux, Windows, Android
License: GPL, LGPL

LibreOffice

LibreOffice is a free and open-source office suite, a project of The Document Foundation. It was forked from OpenOffice.org in 2010, which was an open-sourced version of the earlier StarOffice. The Li...
Language(s): C++, XML, Java
Operating system(s): Linux, Windows 7+ (XP and Vista for 5.x), Mac OS 10.9+, Android (Viewer); Unofficial: Free BSD, OpenBSD, NetBSD, Haiku, Solaris (v. 5.2.5)
License: MPLv2.0 (secondary license GPL, LGPLv3+ or Apache License 2.0)

OnlyOffice

OnlyOffice (formerly TeamLab), stylized as ONLYOFFICE, is an open source office suite developed by Ascensio System SIA, a company with headquarters in Riga, Latvia. Solution features online document e...
Language(s): HTML, JavaScript, C++
Operating system(s): Windows, Mac OS, Linux, Android, iOS
License: AGPLv3