A group of researchers from universities around the world have quietly been putting together an experimental network with the goal of developing cutting edge applications and services.The group, called PlanetLab, consists of about 60 academic research centers plus two vendors. Intel and HP are both donating equipment and the assistance of their respective research units to the project.PlanetLab has built a network that rides over the public Internet. The network deploys 160 servers across 65 sites in 16 countries. The idea behind the overlay network is to allow researchers to test their applications in a "real" environment that experiences traffic congestions, latency and network outages.Researchers are free to develop and test any variety of applications, but the group says there has been some interest in distributed search engines, distributed storage and enhanced multiplayer games, just to name a few.PlanetLab says its work complements that of Internet2, which also operates an experimental network for academia. But there are some differences between the two groups.The first is that Internet2's network, called Abilene, is a closed high-speed network. PlanetLab's network runs over the public Internet. The majority of universities that connect to Internet2 do so over high bandwidth lines upwards of 45M bit\/sec. PlanetLab connections start at DSL and cable modem speeds.The lower speed connections are designed to let researchers test applications and services that will be delivered to "standard" consumers.PlanetLab is also a global project where Internet2's backbone is limited to the U.S.While the majority of PlanetLab's members are from the academic community, the effort is open to all research facilities including commercial labs such as those at Intel and HP, as long as the facility deploys and maintains servers that expand the group's network.