Operating system: Linux (Choose your favorite distribution on DistroWatch.com)
Web browser: Firefox
E-Mail: Thunderbird, GMail, freenet.de
Office suite: LibreOffice
Photo editing: Darktable
Video editing: Kdenlive
Remote support: AnyDesk, TeamViewer
Java development: NetBeans
Database management: dbeaver
Home server: Raspberry Pi with Raspbian, NextCloud