The DansGuardian Anti-Virus Scanner gives you the ability to virus-scan all content that passes through DansGuardian. It uses the scanning code from the MailScanner project to do the actual virus scanning, so it supports all the virus engines that the MailScanner project supports. The scanning is done as the file is being downloaded, so your current network apps don't have to be modified, etc. They just have to support using a proxy.
Swan is a bandwidth manager and Internet gateway that effectively controls and manages the collective bandwidth of an organization. As an Internet gateway it includes a transparent proxy, caching engine, access control lists, caching DNS server, logging and monitoring tools, an authentication mechanism, bandwidth clubbing, and policy management. It is ideal for ISPs, corporations, schools, colleges, etc. Both GUI and console-based interfaces are available for controlling the software. Installation is through a bootable CD that automatically formats the system.
wshare is a simple solution to share an existing network connection from the commandline. There are two modes, master and client. The master shares an existing network connection (probably to the Internet) via an unused wireless device. The client can connect either through the operating system provided facilities or with this script in client mode.