Wikipedia
NetLimiter is client-side traffic shaping and monitoring software for the Windows operating system. Unlike most traffic-shaping utilities, which are based on centrally managed hardware, NetLimiter is a software-only solution. This has the advantage of being less expensive to deploy, but can result in being more difficult to manage its use across more than one computer.
While it has a significant market among more technically minded computer users, in medium-to-large networks it becomes difficult for administrators to maintain multiple copies of configuration files. It is, however, useful for simulating slow links between departments showing how the applications will work when deployed to slower sites.
It is often lumped together with other free or shareware in articles that present the reader with 'essential' applications and poweruser-type utilities.