Open/Free soft must have

Cross-platform file manager with dual-panel design based on Total Commander. Features include advanced searching, tabbed browsing, and plugin support.

A free, open-source viewer for Windows, supports PDFs, eBooks, Comics, with a simple, fast, and portable design prioritized for ease of use.

Free and open-source office suite with advanced word processing, spreadsheets, presentations, vector graphics, math formula editor, and database tools.

A versatile open-source 3D CAD modeler with modular architecture, suitable for engineering applications across multiple platforms, supporting Python scripting.

LibreCAD is an open source 2D CAD application for Windows, Apple and Linux. It is based on Qt, which is a leading cross-platform application and UI development framework.

Mutt is a small but very powerful text-based mail client for Unix operating systems. Some of its features are: color support, message threading, MIME support (including RFC2047 support for encoded headers), PGP/MIME (RFC2015), various features to support mailing lists, including...

Open source vector graphics editor supporting SVG with features like custom brushes, pressure sensitivity, and layer management across multiple platforms.

Advanced text editor with multiple modes, syntax highlighting, word completion, plugin support, built-in help, command-line tools, cross-platform and open source.

Free and open source password manager storing passwords in a local encrypted database with strong AES or Twofish encryption and master key access.

Cross-platform email client providing POP/IMAP support, robust filtering, multiple accounts, and chat. Extendable via add-ons with RSS/Atom, etc.

Efficient file archiver offering superior compression and encryption. Supports multiple formats such as TAR, ZIP, with a unique self-extracting feature.

GNU Emacs is an extensible, customizable text editor—and more. At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing. The features of GNU Emacs include:

Lynx is a fully-featured World Wide Web (WWW) browser for users on Unix, VMS, and other platforms running cursor-addressable, character-cell terminals or emulators. That includes vt100 terminals, other character-cell displays, and vt100 emulators such as Kermit or Procomm...

Tor is free software and an open network that helps you defend against traffic analysis, a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security.

Edit and organize audio metadata easily with comprehensive support for batch editing and various audio formats. Available free for Windows; macOS version costs $20.

Transmission has the features you expect in a BitTorrent client: encryption, a web-based interface, peer exchange, UPnP and NAT-PMP port forwarding, web seed support, watch directories, tracker editing, global and per-torrent speed limits, and more.

Free cross-platform DAW supporting VST plugins, MIDI, and lossless audio. Offers music loopers and sequencers with privacy, no ads, and offline capability.

Links is a text mode web browser, released under GPL. Links2 has the ability to display graphics.

An advanced browser with a built-in VPN for privacy, ad blocker, Speed Dial, AI, cloud sync, and rich extensions, tailored for various devices.

Free open-source suite with advanced photo retouching, composition, batch processing, plugin extensibility, custom scripting, and wide file format compatibility.

Intuitive multi-track video editor with robust hardware-accelerated support; offers chroma key, color grading, and extensive audio/video format compatibility.