GestióIP is an automated, Web based IPv4/IPv6 address management (IPAM) software. It features powerful network discovery functions and offers search and filter functions for both networks and host, permitting Internet Search Engine equivalent expressions. This lets you find the information that administrators frequently need easily and quickly. GestióIP also incorporates an automated VLAN management system.
SoftPerfect Network Scanner is a free multi-threaded IP, NetBIOS and SNMP scanner with a modern interface and several advanced features. It is intended for both system administrators and general users interested in computer security. The program pings computers, scans for listening TCP ports and displays which types of resources are shared on the network (including system and hidden).
Nmap ("Network Mapper") is a free and open source (license) utility for network exploration or security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.
The Dude network monitor is a new application by MikroTik which can dramatically improve the way you manage your network environment. It will automatically scan all devices within specified subnets, draw and layout a map of your networks, monitor services of your devices and alert you in case some service has problems.
Using RhNav - Rhizome Navigation I wrote a data aggregator for Technorati's API. The first result is a video which visualizes blog domains by analysing Technorati's Cosmos (the blogs which link to a particular URL). The video is a screencast of RhNav fetc