Open Source Office & Productivity Software
Zim
Zim is a graphical text editor used to maintain a collection of wiki pages. Each page can contain links to other pages, simple formatting and images. Pages are stored in a folder structure, like in an outliner, and can have attachments. Creating a new page is as easy as linking to a nonexistent page.
StackEdit
StackEdit is an open-source, browser-based Markdown editor with a wide varity of features. It allows you to edit multi-Markdown documents in offline and online modes, lets you store documents in HTML and PDF formats, and collaborate with friends and co-workers though third-party cloud services such as Dropbox, GitHub and Google Drive. A bonus feature of StackEdit is the integration with blogging platforms like Blogger, Tumbler, and WordPress where your documents can be outputted as Markdown or HTML with Handlebars template engine
MacDown
MacDown is a free and open-source markdown editor for macOS. MacDown provides live preview, syntax highlighting and a minimalistic appearance for easy Markdown formatting. The editor is influenced by Mou, and I try to mimic much of its behaviour as much as possible both in UI and the logic. MacDown is loved and use by many thanks to its highly customisable Markdown rendering options, syntax highlighting in fenced code blocks, and sophisticated auto-completion.
WPS Office
WPS Office is a powerful office suite that offers tools for writing documents, managing speadsheets and creating presentations. WPS Office features built-in spell check, keyboard shortcuts, view multiple documents, password protection, save to .pdf, convert to .doc .docx, mail merge, and an intuetive interface that makes you feel right at home. Included in the WPS Office suite is WPS Writer, WPS Spreadsheet, and WPSPresentation.
Apache OpenOffice
Apache OpenOffice is a free and open-source office suite that offers free applications for word processing, spreadsheet, presentations, graphics, and databases. It is one of the successor projects of OpenOffice.org and the designated successor of IBM Lotus Symphony. With Apache OpenOffice all data is stored in an open standard format allowing users to read and write files from all major office software.
Calendso
Calendso is a free and open source self-hosted Calendly alternative. Calendso is white-label by design and can be hosted on-premise or can be hosted and managed by Calendso for a monthly charge. The calendar software is built to be API-driven and ready to be deployed on your own domain and does not add hurdles to the self-hosting process to favor the managed solution. Calendso provides modern features and comes with integrations for popular third-party services like Salesforce, Zapier, HubSpot and many more. While also allow you and your company to build custom integrations for any platform out there, and integrate seamlessly with your existing workflow.
LibreOffice
LibreOffice is a free and open source suite of applications for creating text documents, spreadsheets, presentations and more. With LibreOffice you can open almost any legacy document, and it's the only free and open source office suite available on all major desktop platforms. It features a clean interface and feature-rich tools help you unleash your creativity and enhance your productivity. The suite includes the word processor LibreOffice Writer, the spredsheet LibreOffice Calc, the presentation program LibreOffice Impress, the vector graphics editor LibreOffice Draw, the database management program LibreOffice Base and the math tool LibreOffice Math.
NeoOffice
Specifically designed for macOS, NeoOffice brings a free and open source alternative to popular office suites. NeoOffice is based on OpenOffice and LibreOffice and provides a way for macOS users to view, edit, and save OpenOffice documents, LibreOffice documents, and simple Microsoft Word, Excel, and PowerPoint documents.
LibreOffice Calc
LibreOffice Calc is a free and open-source spreadsheet tool part of the LibreOffice software package. With LibreOffice Calc users can manage spreadshets with its native Open Document Format (.ods), CSV (.csv) and other common formats like the Microsoft Excel format. The software is openly developed by The Document Foundation and the open source community while being released under a combination of license including MPLv2.0 and a secondary license GPL, LGPLv3+ or Apache License 2.0.