System Monitoring:

htop: A user-friendly system monitor that shows real-time usage of CPU, memory, and tasks.
Glances: Provides a comprehensive system overview with CPU, memory, disk, and network statistics.
Package Management:

apt (Debian/Ubuntu-based systems): Handles software installation, updates, and removal.
dnf (Fedora/RedHat-based systems): Used for managing packages on Red Hat-based distributions like Fedora and CentOS.
yum: The older package manager for Red Hat-based systems.
Text Editors:

Vim: A highly configurable text editor for efficient coding and text manipulation.
Nano: A beginner-friendly terminal-based text editor.
Visual Studio Code (VS Code): A lightweight but powerful source code editor available on Linux.
Networking:

nmap: A network exploration tool used for scanning open ports and services.
Wireshark: A network protocol analyzer that helps troubleshoot network issues.
curl/wget: Used for transferring data with URLs, downloading files, or testing APIs.
Security:

ClamAV: An open-source antivirus engine for detecting malware.
Fail2Ban: Protects servers from brute-force attacks by banning IPs after failed login attempts.
iptables: A flexible firewall utility for managing incoming and outgoing network traffic.