Backup utilities:
1. IMAP Backup - https://github.com/joeyates/imap-backup
2. IMAPSync - https://github.com/imapsync/imapsync
3. FSArchiver - https://www.fsarchiver.org/
4. Duplicati - https://www.duplicati.com/
5. Macrium Reflect (nonfree Windows) - https://www.macrium.com/reflectfree

Performance monitoring:
1. Glances - https://nicolargo.github.io/glances/
2. netdata - https://www.netdata.cloud/
3. mysqltuner
4. iotop

Cloud storage:
1. Nextcloud - https://nextcloud.com/

File managers:
1. FileZilla - https://filezilla-project.org/
2. mc - https://midnight-commander.org/
3. Total Commander - https://www.ghisler.com/

Terminal / Shell:
1. zsh
2. Windows Terminal - Windows Store
3. oh-my-zsh - https://ohmyz.sh/
4. oh-my-posh - https://ohmyposh.dev/