Free Software for Windows
FlexGet
FlexGet is a free and open-source multipurpose automation tool for all of your media with support for torrents, nzbs, podcasts, comics, TV, movies, RSS, HTML, CSV, and more.
Total Commander
Total Commander is an Orthodox File Manager (OFM) for Windows. With Total Commander you can organize files and quick and easy navigate through your folder structure. It features an built-in FTP client, and tools for file comparison, archived files navigation and multi file renaming with regular expression.
muCommander
muCommander is a lightweight, cross-platform file manager with a dual-pane interface. The application runs on any operating system with Java support including macOS, Windows, Linux, BSD and Solaris. Featuring a virtual filesystem with support for local volumes, FTP, SFTP, SMB, NFS, HTTP, Amazon S3, Hadoop HDFS and Bonjour. With muCommander you can quickly copy, move, rename files, create directories, email files and zip files can be modified live without the requirement of re-compressing entire archives. muCommander is released as free and open source software under the GNU General License.
USBImager
A really simple open-source, GUI application that writes compressed disk images to USB drives and creates backups. USBImager is avalible for Linux, macOS, and Windows.
Sumatra PDF
With Sumatra PDF you can view documents and manipulate PDF files. Sumatra PDF is a free and open-source document viewer that supports a variety for file extensions, including PDF, CHM, DjVu, EPUB, FB2, MOBI, PRC, OXPS and comic book archive files like CB7, CBR, CBT, CBZ.
Q#
A Microsoft developed domain-specific programming language used for expressing quantum algorithms. Q# share similar structures and elements with popular languages like Python, C#, and F#. The language comes bundled with the QDK (Quantum Development Kit) and quantum simulators, while also being extensible with Q# libraries. With Q# developers can build quantum algorithms used for quantum computing with a basic procedural model for writing programs with loops, if/then statements, and common data types.
Paint.NET
Paint.NET is a free image editing software for Windows. It's fully-featured, and has an intuitive interface that streamlines creative workflows. With Paint.NET, professionals and hobyists alike can create fantastic art work.
Irssi
Irssi is a terminal based IRC client for UNIX-based operating systems. Irssi comes with IRC built-in and is multi-protocol friendly for module authors, it also support integration with SILC and ICB protocols via plugins. The application easily integrates with your window manager, your terminal emulator, your remote connection, your terminal multiplexer, your IRC bouncer and your IRC adapter. Allowing you to use Irssi virtually everywher throughout your system. Irssi is free software licensed under the GPLv2, available for macOS, Linux, BSD, Solaris, and Cygwin.
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.
Thunderbird
A free an open-source email client developed openly by the Mozilla Foundation and the community. Thunderbird is easy to setup and customize and supports POP and IMAP. The email client comes with all features needed to search, filter, write and manage emails, but also have builtin support for live chat between contact and RSS/Atom feed reader.