Beekeeper Studio : Open Source cross-platform SQL Editor and Database Manager. Use Beekeeper Studio to query and manage your relational databases, like MySQL, Postgres, ...
WikkaWiki : WikkaWiki is a flexible, standards-compliant and lightweight wiki engine written in PHP, which uses MySQL to store pages.
CryptPad : CryptPad is the Zero Knowledge realtime collaborative editor.
Encryption carried out in your web browser protects the data from the server, the cloud ...
ntfy : Send push notifications to your phone or desktop using PUT/POST
Imagine running your favorite Windows applications and drivers in an open-source environment you can trust. That's ReactOS. Not just an Open but also a Free operating system.