NetWatch

From SharpeWare:

Keeps network managers informed about their servers and users - wherever they are! Designed for Microsoft Windows NT and 2000, Novell NetWare and UNIX, NetWatch 2 monitors them all - logging important data and generating alerts when problems occur.
NetWatch remotely monitors servers without the need for special agents. Key data such as memory, disk or open files can be logged - or the 'Tell me When' feature can be used to automatically generate alerts by pager, email and more. The Alert Log tracks all problems - and when they are cleared.
NetWatch's 'VolWatch' feature gives a constantly refreshed single view of storage status across all servers - whatever their type. Spotting problems before users do becomes a breeze.
Publish directly to a company intranet site and view up-to-date alerts, server and user data through a browser, wherever you are. NetWatch uniquely maintains the necessary web pages automatically and without the need for web server customisation.
Whatever type of server, NetWatch will remotely display open files, active users, processes/services/NLMs, memory, disk, network stats - and much more.