John Sellens provides papers, articles, booklets, seminars, and services, related to system administation, networking, and monitoring.

Need help with system and network monitoring? Monistics offers a complete slate of local and remote monitoring services, as well as assistance with your own implementation.

NIproxy offers a range of services, proxying, cachine, monitoring, etc., intended to augment and complement the Net Integrator family of servers.

SYONEX offers products and services supporting the system and networking needs of small to medium sized organizations, including firewalls, server appliances, and compute servers.