Open Source Software for Windows
SeaMonkey
The SeaMonkey project is a community effort to develop the SeaMonkey Internet Application Suite and the SeaMonkey web browser. The SeaMoney suite includes a web-browser, advanced e-mail, newsgroup and feed client, IRC chat, and HTML editing made simple.
Syncthing
Syncthing is a free and open-source continuous file synchronisation software that utilise peer-to-peer technology. The software allows users to send files between two or more computers in real time, safely protected from prying eyes. Syncthing is available for Windows, Mac, Linux, Android, Solaris, and BSD.
Beekeeper Studio
Beekeeper Studio is a well-designed and easy to use SQL client for MySQL, PostgreSQL, SQLite, SQL Server, and a variety of other relational database management systems. The software allows you to connect to databases normally or encrypted with SSL, or tunnel through SSH to ensure maximum security while still providing choices. With Beekeeper Studio, you can manage multiple tabs and multitask across operations, while providing auto-complete suggestions for tables and queries. Commonly used queries can be saved and orginized into workspaces, that can be used across connections and projects. Beekeeper Studio is both free and open source and released under the MIT License.
GNUnet
Help build the internet of tomorrow with GNUnet. It's a software framework for fully decentralized, peer-to-peer networking that offers link encryption, peer discovery, resource allocation, and secure communication. The goal of the project is to replace the old insecure Internet protocol stack. GNUnet includes a fully decentralized DNS (Domain Name System) that utilize a directed graph instead of the hierarchical system implemented today. It also has it's own identity system re:claimID, a decentralized Identity Platform that is baked into GNUnet.
Notepad++
Notepad++ is a free and open source text editor that support a wide range of programming languages. Notepad++ is written in C++ and uses pure Win32 API and STL which ensures a higher execution speed and smaller program size. By optimizing as many routines as possible without losing user friendliness, Notepad++ is trying to reduce the world carbon dioxide emissions. When using less CPU power, the PC can throttle down and reduce power consumption, resulting in a greener environment.
Padlock
Padlock is an open source, cross-platform password manager that lets you syncronize passwords across platforms. With Padlock you can store your passwords saftley. Padlock is provided as a manage service for a monthly cost, or can be self-hosted on your own hardware or in the cloud.
PhotoQt
PhotoQt is a free and open-source, simple yet powerful image viewer, based on Qt/QML. It mprovides provides a simple and uncluttered interface filled powerful features. PhotoQt supports GraphicsMagick, Libraw, FreeImage, DevIL, Poppler, libarchive.
Buttercup
Buttercup is a free and open-source password manager, available on all major platforms. With Buttercup you can track and store your login information for any service and device that you use. The application's securely encrypted vault allow you to store account information securely with additional support for 2FA/OTP (TOTP).
Synfig Studio
Synfig Studio is a free and open-source 2D animation software for Windows, Linux and OSX.
QtPass
QtPass is free and open-source, cross-platform password manager that is part of the pass ecosystem. The pass project is an open initiative that builds the standard unix password manager, a universal protocol for password management. This means that you can easily switch away from the QtPass to a new client, as long as it uses the "pass" password store.