GKrellM is a GTK-based stacked monitor program that charts SMP CPUs, disks, load, active net interfaces, and internet connections. There are also builtin monitors for memory and swap, file systems with mount/umount feature, mailbox checking including POP3 and IMAP, clock/calendar, laptop battery, sensors (temperatures, voltages, and fans), and uptime. It has LEDs for the net monitors and an on/off button and online timer for PPP. There is a GUI popup for configuration, plugin extensions can be installed, and many themes are available. It also features a client/server monitoring capability.
aircrack-ng is a set of tools for auditing wireless networks. It's an enhanced/reborn version of aircrack. It consists of airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), airdecap (decrypts WEP/WPA capture files), and some tools to handle capture files (merge, convert, etc.).
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
collectd is a small and modular daemon which collects system information periodically and provides means to store the values. Included in the distribution are numerous plug-ins for collecting CPU, disk, and memory usage, network interface and DNS traffic, network latency, database statistics, and much more. Custom statistics can easily be added in a number of ways, including execution of arbitrary programs and plug-ins written in Perl. Advanced features include a powerful network code to collect statistics for entire setups and SNMP integration to query network equipment.
Kismet is an 802.11 layer 2 wireless network detector, sniffer, and intrusion detection system. It will work with any wireless card which supports raw monitoring (rfmon) mode, and can sniff 802.11b, 802.11a, 802.11g, and 802.11n traffic (device drivers permitting). It identifies networks by passively collecting packets and detecting standard named networks, detecting (and given time, decloaking) hidden networks, and inferring the presence of non-beaconing networks via data traffic.
Ganglia is a scalable distributed monitoring system for high-performance computing systems such as clusters and grids. It is based on a hierarchical design targeted at federations of clusters. Ganglia is currently in use on over 500 clusters around the world and has scaled to handle clusters with 2000 nodes.
x11vnc allows one to remotely view and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. It is designed to be compatible with all Unix variants and Mac OS X, and depends on a small set of standard libraries. It supports SSL/TLS and VeNCrypt encryption, Unix password logins, single port access, Zeroconf, file transfer, and UltraVNC extensions. It is part of the LibVNCServer project.
bandwidthd tracks usage of TCP/IP network subnets and builds HTML files with graphs to display network utilization. Charts are built by individual IP to show their utilization over 2, 8, 45, and 400 day periods. It color codes HTTP, HTTPS, TCP,UDP, ICMP, VPN, and P2P traffic. Unlike MRTG, it tracks each individual IP address and subnets, not the status of any particular link. Static mode is fast and easy to set up and has few dependencies. Database mode supports filtering by subnet, multiple sensors, custom reports and intervals, and can process thousands of IPs efficiently. Network utilization can be logged in CDF or a backend database.