Alternative to nagios / local monitoring for linux server and windows

Hi,

I have 2 nagios server :
- one on network A
- one on the network I

and I monitore some servers (linux and windows server) running on network A from nagios on network I.

For political reason, I must shutdown the nagios server running on network A :-(

I also want to stop the monitoring of servers running on network A from nagios on network I, but I want to keep an monitoring (disk, services/process, cpu, ...) so I'm looking for a tools running on console (no web interface) where I can setup monitoring and alertes (email) on each server. A free tools, of course.

Anyone have a suggestion for that ?

best regards,