Open Source Software for Windows
TimescaleDB
TimescaleDB is a leading open-source relational database for time-series data. The database is provided as fully managed or self‑hosted software, giving the power of choice back to developers and organizations. Timescale gives you all the reliability and flexibility of PostgreSQL. It allows you to use regular SQL to construct queries to better understand your products and your users. While achieve 10-100x faster queries than PostgreSQL, InfluxDB, and MongoDB with native optimizations for time-series.
SQLite
SQLite is a free and open-source relational database management system that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine. Rather than being a typical client–server database engine, SQLite is self-contained and can be embedded into applications. Making it perfect for development frameworks that want to provide a default database without setup, or applications that needs an embedded database. SQLite is built into all mobile operating systems and most computers and comes bundled with a countless applications. SQLite is also ACID-compliant and implements most of the SQL standard, generally following PostgreSQL syntax.
CouchDB
CouchDB is a free and open-source document-oriented NoSQL database developed by the Apache Foundation. The database is written and implemented in the language Erlang and provides the use of multiple formats and protocols to store, transfer, and process data. With CouchDB you query data with JavaScript using MapReduce, and HTTP for an API. Which can be done across multiple distributed CouchDB instances as the database has the ability to synchronize multiple copies of the same database, across servers.
KeyDB
KeyDB is fast, free, and open-source NoSQL database with full compatibility for Redis APIs, clients, and modules. The database was originally forked from the Redis code-base and has been improved to handle multithreading, memory efficiency, and higher throughput. KeyDB is now a fully multithreaded and allow many machine cores to operate a single node resulting in 5X the throughput of Redis (v5) and up to 3x the throughput of Redis (v6). KeyDB also includes Redis Enterprise such as Active Replication, FLASH storage support, and other features like direct backup to AWS S3.
ownCloud
With ownCloud, organizations can collaborate and be more production on their own secure enterprise file sharing (EFSS) platform. The ownCloud platform is self-hosted and allow for secure file sharing within an organization. The platform can be hosted on premise or on a cloud instance, controlled by the organization. The software is written in PHP and Javascript and is fully open source, released under the AGPLv3 license. ownCloud can run on most server hardware and operating systems, and the client for accessing ownCloud is available for Android, iOS, macOS, Linux and Windows.
aaPanel
aaPanel is a free and open source web hosting control panel. It's a simple, yet powerful control panel that provides one click installs for LNMP and LAMP development stacks through an intuetive graphical user interface (GUI). aaPanel was designed to help you save time when deploying web sites and applications to the web. Allowing you to focus on building your project, rather than focusing on installation and configuration of servers and tooling. Over 3 million people use aaPanel to create quickly deployable web environments for Apache HTTP Server, Nginx and OpenLiteSpeed.
Open Broadcaster Software
OBS is a video and streaming recording platform that records video from games, webcams, full screens, or various windows. It can also be utilized to make live streaming to video sharing websites or to a custom address that you may share with others who will watch the video you shared.
Liquibase
Liquibase is an open source tool for tracking, managing and applying database changes, also known as migrations. With Liquibase, all database changes are stored in a human readable yet trackable form and checked into source control.
Publii
Publii is a free and open-source headless CMS designed for speed and ease-of-use. With Publii, you can build beautiful modern sites that will run fast in browser thanks to Google's AMP technology. What make Publii unique is that the content management is done via a desktop-based client that works for MacOS, Linux and Windows.
Librevault
Librevault allows you to transfer data directly from one device to another, securely. Librevault is a free and open-source peer-to-peer file synchronization software, designed with convenience. privacy and security in mind. The software encrypts all data with AES-256 and uses TLS for all transmissions. Their goal is to make a better alternative to BitTorrent Sync and Syncthing.