LibreOffice is a powerful office suite.  Its clean interface and
  feature-rich tools help you unleash your creativity and enhance your
  productivity.  LibreOffice includes several applications that make it the most
  powerful Free and Open Source office suite on the market: Writer (word
  processing), Calc (spreadsheets), Impress (presentations), Draw (vector
  graphics and flowcharts), Base (databases), and Math (formula editing).
      LibreOffice supports opening and saving into a wide variety of formats, so
  you can easily share documents with users of other popular office suites
  without worrying about compatibility.
    

LibreOffice

Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files. In Obsidian, making and following connections is frictionless, and with the connections in place, you can explore all of your knowledge in the interactive graph view. Obsidian supports CommonMark and GitHub Flavored Markdown (GFM), along with other useful notetaking features such as tags, LaTeX mathematical expressions, mermaid diagrams, footnotes, internal links and embedding Obsidian notes or external files. Obsidian also has a plugin system with 20+ supported plugins to expand its capabilities.
      The documentation can be accessed by opening the demo vault that is shipped in Obsidian.
      Obsidian will always remain free for personal use, no account or license is required for qualifying use cases described in the End User License Agreement. However, commercial users should purchase a license on Obsidian's website. Users also have the option to purchase a Catalyst license to get early access to insider builds and support the development. Additionally, Obsidian offers an optional paid hosting service for your notes. Details about this optional hosting service can be found on the Obsidian website.
      This distribution is verified by the Obsidian team but isn't supported
      Wayland support can enabled with --socket=wayland in Flatseal which can enable features like pinch zoom
      GPU acceleration can be disabled if necessary by setting OBSIDIAN_DISABLE_GPU=1 in Flatseal
      Pdflatex support in pandoc currently requires installing the org.freedesktop.Sdk.Extension.texlive SDK
      Note: Regular users should disable "Automatic Updates" within Obsidian as public release updates are handled by Flatpak itself. Insiders should keep this enabled to receive insider builds, as those will not be made available on Flathub.
      This flatpak goes into great lengths to provide a nice experience for end users. In order for the Git plugin to work it requires permission to the ssh-auth socket (--socket=ssh-auth). It also exposes the home directory in the sandbox (required for Drag and Drop operations). If you don't use the Git plugin you can disable the ssh-auth socket permission, e.g. using Flatseal. You can also remove access to the home directory if you want and the flatpak will continue to work, albeit with reduced functionality. In case you do remove access to the homedir, note that in order for things to not break for the Git plugin, --persist=.ssh flag has been passed and a bind mount to ~/.var/app/md.obsidian.Obsidian/ is created by flatpak, allowing that location to be used for persistent data (but your home directory's .ssh remains unaccessible)
    

Obsidian

Create, view and edit text documents, spreadsheets and presentations of any size and complexity. Work on documents of most popular formats: DOCX, ODT, XLSX, ODS, CSV, PPTX, ODP, etc. Deal with multiple files within one and the same window thanks to the tab-based user interface.
    

ONLYOFFICE Desktop Editors

Thunderbird is a free and open source email, newsfeed, chat, and calendaring client, that’s easy to set up and customize. One of the core principles of Thunderbird is the use and promotion of open standards - this focus is a rejection of our world of closed platforms and services that can’t communicate with each other. We want our users to have freedom and choice in how they communicate.Thunderbird is an open source project, which means anyone can contribute ideas, designs, code, and time helping fellow users.

Thunderbird

Thunderbird is a free and open source email, newsfeed, chat, and calendaring client

Unofficial Microsoft Teams client for Linux using Electron.
      It uses the Web App and wraps it as a standalone application using Electron.
    

teams-for-linux

Unofficial Microsoft Teams client for Linux using Electron


      The web browser for techies and people who need a browser that helps them get things done.
      The user interface is fully customizable, including keyboard shortcuts, mouse gestures, and programmable macros.
    
      
        Seize back control of your tabs with features like Workspaces, Tab Stacks, and Tab Tiling.
        Stay on top of all your emails, appointments, to-dos, and news with Mail, Calendar, Tasks, and Feed Reader. (Compatible with IMAP, POP3, CalDAV, and Atom/RSS.)
        Jot down ideas and inspiration with the integrated Notes manager.
        End-to-end encrypted (E2EE) sync of bookmarks, passwords, notes, and more with Vivaldi for desktop, iOS, and Android.
        Efficient built-in Tracker and Ad Blocker.
        Compatible with most browser extensions from the Google Chrome Web Store.
      
      
      NOTE: This package is maintained by but not yet officially endorsed or supported by Vivaldi Technologies.
    
    

Vivaldi


   Okular is a universal document viewer developed by KDE. Okular works on multiple platforms, including but not limited to Linux, Windows, Mac OS X, *BSD, etc.
  
      Features:
      
        Supported Formats: PDF, PS, Tiff, CHM, DjVu, Images, DVI, XPS, Fiction Book, Comic Book, Plucker, EPub, Fax
        Sidebar with contents, thumbnails, reviews and bookmarks
        Annotations support
      
    

Okular

calibre is the one stop solution to all your e-book needs.
      You can use calibre to catalog your books, fetch metadata for them automatically, convert them from and to all the various e-book formats, send them to your e-book reader devices, read the books on your computer, edit the books in a dedicated e-book editor and even make them available over the network with the built-in Content server. You can also download news and periodicals in e-book format from over a thousand different news and magazine websites.
    

calibre

The one stop solution to all your e-book needs

Discover a new chapter in reading with Foliate, the modern e-book reader tailored for GNOME. Immerse yourself in a distraction-free interface, with customization features designed to match your unique preferences.
      Features include:
      
        Open EPUB, Mobipocket, Kindle, FB2, CBZ, and PDF files
        Paginated mode and scrolled mode
        Customize font and line-spacing
        Light, sepia, dark, and invert mode
        Reading progress slider with chapter marks
        Bookmarks and annotations
        Find in book
        Quick dictionary lookup
      
    

Foliate

WPS Office including Writer, Presentation
    and Spreadsheets, is a powerful office suite, which is able to process
    word file, produce wonderful slides, and analyze data as well. It is
    deeply compatible with all of the latest Microsoft Office file formats.
    It can easily open and read the documents created with Microsoft Office.
      NOTE: This wrapper is not verified by, affiliated with, or
    supported by Kingsoft Office Corporation
    

WPS Office

Adobe Reader software is the official Adobe software for viewing, printing, and annotating PDF documents.NOTE: This software is unmaintained by the vendor and may contain security vulnerabilities.NOTE: This wrapper is not verified by, affiliated with, or supported by Adobe.

Adobe Reader

Master PDF Editor is straightforward, easy to use application for working with PDF documents equipped with powerful multi-purpose functionality. With Master PDF Editor you can easily view, create and modify PDF documents. The application enables you to merge several files into one, split a source document into multiple documents, and also to comment, sign and encrypt PDF files.NOTE: This wrapper is not verified by, affiliated with, or supported by Code Industry.

Master PDF Editor

View, create, modify, sign, scan, OCR and print PDF documents


      Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor. The notes are in Markdown format.
    
      
      Notes exported from Evernote via .enex files can be imported into Joplin, including the formatted content (which is converted to Markdown), resources (images, attachments, etc.) and complete metadata (geolocation, updated time, created time, etc.). Plain Markdown files can also be imported.
    
      
      The notes can be synchronised with various cloud services including Nextcloud, Dropbox, OneDrive, WebDAV or the file system (for example with a network directory). When synchronising the notes, notebooks, tags and other metadata are saved to plain text files which can be easily inspected, backed up and moved around.
    
      
      The application is available for Windows, Linux, macOS, Android and iOS (the terminal app also works on FreeBSD). A Web Clipper, to save web pages and screenshots from your browser, is also available for Firefox and Chrome.
    
    

Joplin

open source note taking and to-do application


      PDF Arranger is a small application, which helps the user to merge or split pdf
      documents and rotate, crop and rearrange their pages using an interactive and
      intuitive graphical interface.
    
      
      It is a frontend for pikepdf.
    
    

PDF Arranger

PDF Merging, Rearranging, Splitting, Rotating and Cropping

A document viewer for the GNOME desktop. You can view, search or annotate documents in many different formats.
      Evince supports documents in: PDF, PS, EPS, XPS, DjVu, TIFF, DVI (with SyncTeX), and Comic Books archives (CBR, CBT, CBZ, CB7).
    

Document Viewer

Document viewer for popular document formats


      GNOME Calendar is an elegant tool to help you plan and stay on top of your schedule for
      upcoming days and weeks, whether your months are filled with meetings and appointments,
      public events, travel logistics, or other commitments in your life.
    
      
      Easily create and manage unlimited calendars and events with GNOME Calendar's infinite
      scrolling month view, week timetable, and scheduling list view.
    
      
      Integrating the latest GNOME technologies and design best practices, GNOME Calendar builds on
      top of the mature Evolution data server to manage large quantities of events and to provide
      integration with other applications. You can add calendars from various online calendaring
      services (like NextCloud, Google Calendar, and CalDAV / WebDAV servers), enabling you to
      synchronize your events across multiple devices and platforms. GNOME Calendar also supports
      local and offline calendaring, so you can use it anywhere and anytime while travelling
      (or after civilization's collapse.)
    
    

Calendar

What's:
      Zapzap is a container for execution of the web web, that is, a kind of Webapp.Thus, all features of the Whatpp Web are available and several others that integrates it with the system.
      Its differential is the support to multiple accounts, in the background running, spellchecker and customizations based on the theme of the system.
      Data security:
      No modification and manipulation is performed on the execution of the Whatpp Web. In addition, all source code is available in Github and can be auditable.
      About:
      ZapZap was initially developed for personal use.I decided to share it so that other people, like me, could have a WhatsApp customer more integrated into the system.
    

ZapZap


      Xournal++ is a hand note-taking software written in C++ with the target of
      flexibility, functionality and speed. Stroke recognizer and other parts are
      based on Xournal Code, which you can find at sourceforge. It supports GNU/Linux
      (e.g. Ubuntu, Debian, Arch, SUSE), macOS and Windows. Supports pen input
      from devices such as Wacom Tablets.
    
      
      Xournal++ features:
    
      
        Supports pressure-sensitive styluses and digital pen tables (e.g. Wacom, Huion, XP Pen, etc. tablets)
        Paper backgrounds for note-taking, scratch paper, or whiteboarding
        Annotate on top of PDFs
        Select text from the background PDF, copy, highlight or underline it or strike it through
        Follow links from the background PDF
        Export to a variety of formats including SVG, PNG and PDF, both from the GUI and command line
        Different drawing tools (e.g. pen, highlighter) and stroke styles (e.g. solid, dotted)
        Shape drawing (line, arrow, circle, rectangle, spline)
        Use the set-square and compass tools for measurements or as a guide for drawing straight lines, circular arcs and radii
        Fill shape functionality
        Shape resizing and rotation
        Rotation and grid snapping for precise alignment of objects
        Input stabilization for smoother writing/drawing
        Text tool for adding text in different fonts, colors, and sizes
        Enhanced support for image insertion
        Eraser with multiple configurations
        LaTeX support (requires a working LaTeX installation) with customizable template and a resizable editor with syntax highlighting
        Sidebar containing page previews with advanced page sorting, PDF bookmarks and layers (can be individually hidden/edited)
        Allows mapping different tools/colors etc. to stylus/mouse buttons
        Customizable toolbar with multiple configurations, e.g. to optimize toolbar for portrait/landscape
        Custom color palette support using the .gpl format
        Page template definitions
        Bug reporting, autosave, and auto backup tools
        Audio recording and playback alongside with handwritten notes
        Multi language support (over 20 languages supported)
        Plugins using Lua scripting
      
      
    

Xournal++

Logseq is a platform for knowledge management and collaboration. It focuses on privacy, longevity, and user control.
      Your data are plain text files and we currently support both Markdown and Emacs Org mode (more to be added soon).
    

Logseq

A local-first, non-linear, outliner notebook for organizing and sharing your personal knowledge base


      Contacts keeps and organize your contacts information. You can create,
      edit, delete and link together pieces of information about your contacts.
      Contacts aggregates the details from all your sources providing a
      centralized place for managing your contacts.
    
      
      Contacts will also integrate with online address books and automatically
      link contacts from different online sources.
    
    

Contacts

Unofficial Microsoft Outlook client for Linux using Electron.It uses the Web App and wraps it as a standalone application using Electron.A clone of  but for outlook. All credits for authors of that repo

outlook-for-linux

Unofficial Microsoft Outlook client for Linux using Electron

Betterbird is a fine-tuned version of Mozilla Thunderbird, Thunderbird on steroids, if you will. Betterbird is better than Thunderbird in three ways: It contains new features exclusive to Betterbird, it contains bug fixes exclusive to Betterbird and it contains fixes that Thunderbird may ship at a later stage.
    

Betterbird

Betterbird is a soft fork of Mozilla Thunderbird. Simply better.

🚀️ Planify is here...
      
        🚀️ Complete redesign of the UI.
        🤚️ Drag and Order: Sort your tasks wherever you want.
        💯️ Progress And Emoji indicator for each project.
        💪️ Be more productive and organize your tasks by 'Sections'.
        🌙️ Better integration with the dark theme.
        🎉️ and much more.
      
      ☁️ Support for Todoist:
      
        Synchronize your Projects, Task and Sections thanks to Todoist.
        Support for Todoist offline: Work without an internet connection and when everything is reconnected it will be synchronized.
      
      * Planify not created by, affiliated with, or supported by Doist
      💎️ Other features:
      
        🔍️ Quick Find
        🌙️ Night mode
        ⏰️ Reminders
      
    

Planify


      Rnote is a vector-based drawing app for sketching, handwritten notes and to annotate documents
      and pictures.
    
      
      Disclaimer: The file format is still unstable. It might change and break compatibility between
      versions.
    
    

Rnote

Todoist is used by 20 million people to organize, plan, and collaborate on projects, both big and small.Use Todoist to:Capture and organize tasks the moment they pop into your head.Remember deadlines with reminders and due dates.Build lasting habits with recurring due dates like "every Monday".Collaborate on projects by assigning tasks to others.Prioritize your tasks with priority levels.Track your progress with personalized productivity trends.Integrate your tools like Gmail, Google Calendar, Slack, Amazon Alexa, and more.Available on any device, Todoist will quickly become your hub for getting work and life organized.Happy organizing!•Questions? Feedback? Visit get.todoist.help or reach out on Twitter at @todoist.NOTE: This wrapper is not created by, affiliated with, or supported by Doist.

Todoist: To-Do List & Tasks

“The best to-do list app right now” - The Verge

Evolution is a personal information management application that provides integrated mail, calendaring and address book functionality.
      Evolution supports a wide range of industry standard data formats and network protocols for information exchange, with an emphasis on standards compliance and security. Evolution can also integrate smoothly with Microsoft Exchange by way of the “Exchange Web Services” (EWS) extension.
    

Evolution


      Zotero [zoh-TAIR-oh] is a free, easy-to-use tool to help you collect,
      organize, cite, and share your research sources.
    
      
      NOTE: If your Zotero folder is not located inside your home directory (~/)
      and is outside your xdg-user-dirs, please grant permission to access that
      folder by the flatpak-override command (usage:
      "flatpak override --user --filesystem=/PATH/TO/ZOTEROFOLDER org.zotero.Zotero").
    
      
      NOTE: This flatpak is not verified by, affiliated with, or supported by the Zotero project.
    
    

Zotero

Need to safely store all of your important documents, photos, songs, and files? Easy! With this app you can use the internet to save everything that’s important to you. You can then access those files from any computer that has an internet connection. Use this service to backup your files, share photos or collaborate on a project by sharing a Dropbox folder with whomever you’d like. Create a free account and start saving and sharing today!
      NOTE: This wrapper is not verified by, affiliated with, or supported by Dropbox, Inc.
    

Dropbox

Use the power of mind-mapping to make your ideas come to life.
      
        Quickly create visual mind-maps using the keyboard and automatic layout.
        Choose from many tree layout choices.
        Support for Markdown formatting.
        Support for insertion of Unicode characters.
        Add notes, tasks and images to your nodes.
        Add node-to-node connections with optional text and notes.
        Stylize nodes, links and connections to add more meaning and improve readability.
        Add stickers and node groups to call out and visibly organize information.
        Quick search of node and connection titles and notes, including filtering options.
        Zoom in or enable focus mode to focus on certain ideas or zoom out to see the bigger picture.
        Enter focus mode to better view and understand portions of the map.
        Unlimited undo/redo of any change.
        Automatically saves in the background.
        Colorized node branches.
        Open multiple mindmaps with the use of tabs.
        Built-in and customizable theming.
        Gorgeous animations.
        Import from OPML, FreeMind, Freeplane, PlainText (formatted), Markdown, Outliner, PlantUML, Portable Minder, filesystem, and XMind formats.
        Export to CSV, FreeMind, Freeplane, JPEG, BMP, SVG, Markdown, Mermaid, OPML, Org-Mode, Outliner, PDF, PNG, PlainText, PlantUML, Portable Minder, filesystem, XMind and yEd formats.
        Printer support.
      
    

Minder

ghostwriter is a distraction-free text editor for Markdown featuring
       a live HTML preview as you type, theme creation, focus mode, fullscreen
       mode, live word count, and document navigation in an aesthetic writing
       environment.  It comes with the cmark-gfm Markdown processor built in, and
       can integrate with Pandoc, MultiMarkdown, Discount, and cmark 
       processors if they are installed.
    

ghostwriter

Distraction-free text editor for Markdown

生產力