NetsGraph is a simple PHP class to generate statistical graphics from network data transfers. It accepts as input a list of samples representing the average network data transfer on a specified interval and is able to create native SVG graphics or PNG images.
The Deimos Project is a computer statistics/monitoring tool allowing you to gather information and statistics about your computers, including network information and bandwidth, uptime information, keyboard and mouse usage, and hardware information.
BitMeter OS is a bandwidth meter. It logs how much data is uploaded and downloaded from your system and records this information in an SQLite database. The database can be queried from the command-line or monitored in real time.
IFMon (Interface Monitor) displays the traffic, state, connection, and other information of a network interface as a small console window. The information for the network interface being monitored is obtained from the files in /proc to help simplify portability.