IPAppmon
Are you an over-worked network administrator? Get calls complaining about system outages you have no way of monitoring? Don't know if your payroll server is up or down? Rest easy. AppMon makes it easy to run applications and monitor them from your current network monitoring package.... ... STEP 3: Configure your network monitoring tool* to monitor the appropriate TCP/IP port where AppMon resides. ... If any one of the Applications started by AppMon fails (or is accidentally closed), you will be notified visualy, audibly, by email and through your network monitoring tool.
http://www.ipworx.com/product/appmon/appmon4.zip - 4Mb - Download - Screenshot

Easy Network Service Monitor
Easy Service Monitor is a network fault management tool that continuously monitors network devices and services. If something went wrong, it will alert you by email/phone/pager BEFORE problems get seriously out of hand. A detailed log file will record every event of the monitored targets and can... You can configure the system so that when something goes wrong, a set of actions, such as execute a program, reboot server or update web page, will be triggered.
http://www.javvin.com/emonitor.exe - 2Mb - Download - Screenshot

Alchemy Network Monitor
Alchemy Network Monitor monitors your network servers and business-critical applications availability and performance and immediately alerts you if a server gets out of order. Alchemy Network Monitor can also perform certain actions (e. g. launch an external application or execute an SQL query)...
http://www.mishelpers.com/ftp/netmon.zip?c=archive - 2Mb - Download - Screenshot

Alchemy Network Monitor PRO
Alchemy Network Monitor monitors your network servers and business-critical applications availability and performance and immediately alerts you if a server gets out of order. Alchemy Network Monitor can also perform certain actions (e. g. launch an external application or execute an SQL query)...
http://www.mishelpers.com/ftp/netmonpro.zip?c=archive - 3Mb - Download - Screenshot

Nexeye Monitoring Enterprise
How efficient is your internet connection being utilised? Does your network users utilising the internet to the purpose of your organisation? Which web sites are your users browsing? Do you have a control of the content of the e-mails sent from your network? ... Monitor network activities Monitor network users web, e-mail and MSN Messenger activities on a real-time basis with nexeye Monitoring. ... Monitor network utilisation Monitor on a real-time basis the network traffic from/to the Internet as well as the traffic generated by the individual users.
http://www.nexeye.com/nexeye-setup.exe - 3Mb - Download - Screenshot

XR SNMP Tools
XR SNMP Tools is a set of high performance tools for monitoring network SNMP manageable devices. XR SNMP Tools monitors the Network Health as well as many other network parameters like bandwidth usage, error and collision rates, memory and CPU usages. ... The most common usage is real-time network monitoring of WAN and LAN networks, but you can also monitor many other aspects of managed switches, printers, and other network components as long as they are SNMP enabled. ... Powerful network diagnostics such as the Network Health are easily achieved using XR SNMP Tools.
http://www.xratel.com/dload/snmp/xr_snmp_tools.exe - 8Mb - Download - Screenshot

IPMonitor
IPMonitor is a sophisticated network monitoring solution that allows network administrators, webmasters, and Internet service providers to monitor any networked device on the Internet, corporate intranet, or TCP/IP LAN and receive alerts immediately via audible alarm, message, e-mail, or... Main features: runs as a system tray application automatically on startup, monitors up to 500 network devices or services simultaneously, allows quick network resource configuration, allows all parameters to be set independently for each network resource, permits you to temporarily disable monitoring of...
http://ipmonitor.tsarfin.com/downloads/ipmonitor.zip - 1Mb - Download - Screenshot

Monitor one
Monitor one, is an easy to use and rich-featured SNMP Network management and monitoring application. It allows Network managers to monitor all of their networking devices (Routers, Switches, Servers, etc.. ) at a glance through an intuitive (native and web-based) graphical network map on a... Monitor one includes powerful features like: SNMP MIB data retrieval, MIB compiler, Status polling, Health polling, Threshold monitoring and Trending, Syslog server, Device discovery, Alerting and a MIB browser.
http://dl.filekicker.com/send/file/173632-4833/MonitoroneLV.exe - 16Mb - Download

PA Server Monitor
PA Server Monitor is a Windows service that monitors the health and availability of Windows servers, network services (on Windows, Linux and other operating systems), and devices. No agents are needed to monitor remote servers. Also includes rich reporting on most monitored resources. ... PA Server Monitor can watch: Event logs on local and remote Windows servers CPU and memory usage Free local and server disk space Changed files and directories (great intrusion detection) Running Windows services Custom script results Local and remote directory quota monitoring Network Interface...
http://www.poweradmin.com/servermonitor/servermonitorpro.exe - 5Mb - Download - Screenshot

DEKSI Network Monitor
DEKSI Network Monitor is an advanced, powerful, and feature rich tool that monitors servers located on your local network and the Internet. DEKSI Network Monitor will allow the Administrator to increase the reliability and productivity of your corporate servers. ... Using DEKSI Network Monitor the Administrator is aware about the state of their servers at any time. ... If DNM cannot correct the problems it immediately notifies the Administrator about the problem via e-mail, sms or a network messaging service.
http://www.deksoftware.com/new/dnm.exe - 2Mb - Download - Screenshot