cFosSpeed

cFosSpeed is a network driver, which attaches itself to existing Internet connections.

Bandwidth Manager

Bandwidth management, bandwidth limiting and traffic shaping software for Windows

DU Meter is a network bandwidth monitor for your computer.

Visualize network activity in detail, get notified when new apps access the network, look out for…

ClearFoundation is a developer community for ClearOS, a Linux Internet Network, Gateway and Server for small business and distributed networks.

NetBalancer is a Windows application for local network traffic control and monitoring.

Essential network bandwidth monitor.

NetWorx is a simple and powerful tool that helps you objectively evaluate your bandwidth situation.

An advanced network monitoring solution to monitor network up/downtime, traffic and usage.

Speed Limiter application can simulate slow TCP/IP connections.

TMeter is a powerful traffic accounting and Internet sharing tool for Microsoft Windows.

Throttled Pro optimizes your internet connection and provides QoS (Quality of Service) to Mac OS X.

Lightweight and non-intrusive firewall

Traffic Shaper XP is a free bandwidth limiter for Windows 2000, XP and 2003 Server.

Windows 10 Firewall Control: simple and exhaustive solution for applications network activity controlling and monitoring.

A bandwidth limiting and traffic prioritization tool for linux.

Personal Firewall software

pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more

trickle is a portable lightweight userspace bandwidth shaper.