Open Source Software for Windows
Prometheus
Prometheus is a Cloud Native Computing Foundation project for systems and service monitoring. With Prometheus you can collect metrics from configured targets at given intervals, evaluates rule expressions, displays the results, and can trigger alerts when specified conditions are observed. Prometheus include features like multi-dimensional data models. PromQL, a powerful and flexible query language to leverage this dimensionality. No dependency on distributed storage. An HTTP pull model for time series collection and much more.
FreeCAD
FreeCAD is a highly customizable, scriptable and extensible computer aided design software software for the, MacOS, Linux and Windows operating systems. With FreeCad you can model and design real-life objects in 3D through parametric modeling where all 3D objects you design are controlled by parameters. FreeCAD is released as free and open source software under LGPv2+ license, and can be used for commercial and hobby projects alike.
HedgeDoc
HedgeDoc, formerly known as CodiMD is an open-source collaborative markdown editor. HedgeDoc provides collaborative features that makes it easy for teams to work together by creating notes, graphs and even presentations in real-time. With HedgeDoc, all you need to get started is to share a link to your co-workers, and they can join you in the process.
Ruby
Ruby is a free and open-source interpreted, high-level, general-purpose programming language. The language was created by Yukihiro "Matz" Matsumoto from Japan in the mid-1990s. Today, Ruby has a friendly and growing community from all over the world and is openly developed and maintained. According to its creator Yukihiro, the language share many similarities with Perl, Smalltalk, Eiffel, Ada, Basic, and Lisp, all of which Ruby was influenced by.
Mailspring
Mailspring is a desktop email client designed for macOS, Linux and Windows. It provides modern features like unified inbox, snoozing, templates, offline search, and support for Gmail labels. With Mailspring you can breath fresh air into your mailbox with support for various third-party IMAP provides such as Gmail, Office 365 and Microsoft Outlook. Mailspring intuitive features like read receipts, link tracking, send later, reminders, contact profiles and more.
Swarmlet
Swarmlet is a free and open-source, self-hosted Platform as a Service that runs on any single server. It's mainly intended for use with multiple servers, a server cluster / swarm. Swarmlet is inspired by Dokku and brings the same simplicity to Docker Swarm. Swarmlet also uses Traefik v2 and Let's Encrypt to provide automatic SSL and load balancing on your apps.
I2P
The Invisible Internet Project or I2P for short is a fully encrypted private network layer that has been developed with privacy and security by design in order to provide protection for your activity, location and your identity. I2P ships with a router that connects you to the network and applications for sharing, communicating and building a fully encrypted private network layer.
Remotely
Remotely is an all-in-one remote access software. With Remotely you can instantly connect to remote desktops either unattended or by invite, where invites are started from a single-file, portable executable that's easy for customers to download and use. Remotely also allow you to do remote scripting so that you can save time on quick fixes and ad-hoc scripting with an interactive console that lets you execute commands against multiple remote machines simultaneously, with instant results. Written with rich auto-complete for PowerShell Core, Windows PowerShell, Windows CMD, and Bash increases speed and accuracy of commands.
OpenConnect
OpenConnect is an open-source SSL VPN client for Linux and Windows. OpenConnect is based upon SSL security protocol and was built as a replacement VPN client for Cisco’s AnyConnect SSL VPN. With support from the open source community it has now become the standard underlying technology for many VPN providers. With OpenConnect you can implement your own server, initiate data encryption, and import and manage server configurations.
Gitter
Gitter is an open-source instant messaging and chat room system for developers designed to make community messaging, collaboration and discovery as smooth and simple as possible. Gitter is provided as software-as-a-service and integrates with GitLab and GitHub repositories to make discussion around code even easier. With Gitter, you can can easily create, organise and grow your communities, inviting others to join just in one click. Over 1.5M users across 100K communities use Gitter to discuss code and development progress.