Internet2, Abilene, LambdaNetRail

From wikipedia:

There have been times when the media have reported on a network called "Internet2." This is misleading since Internet2 is in fact a consortium and not a computer network. "Internet2" is sometimes used, albeit a misnomer, for the Abilene Network. The Abilene project is supported greatly by Qwest Communications through the use of Qwest's fiber optical networks. Internet2's Abilene transport agreement with Qwest is due to expire somewhere around October 2007. Internet2 has contracted with Level3 for the fiber required to support the successor to Abilene.

More from wikipedia:

there has been a recent trend in the media to report on a network called "Internet2." Some sources go so far as to suggest Internet2 is a network wholly separate from the Internet. This is misleading since Internet2 is in fact a consortium and not a computer network. It is possible that many news sources have adopted the term Internet2 because it seems like a logical name for a next-generation Internet backbone. Articles that reference Internet2 as a network are in fact referring to the previously mentioned network backbone known as the Abilene Network. This forms a high-speed backbone by deploying many of the technologies developed by Internet2. Abilene, although a private network used for education and research, is not entirely an isolated network, since its members usually provide alternative access to many of their resources through the public Internet. Abilene is not technically part of the Internet since it does not peer with the public Internet networks. The official website of Qwest, one of many major contributors to the Abilene Network, has a good FAQ section that clarifies the distinction between Internet2 and Abilene.

At the completion of the transition from the legacy Abilene network to the new Level3-based infrastructure, the Abilene name will cease to be used in favor of The Internet2 Network. Abilene was 10GB per sec. The I2 will be made up of 40 Lambda capacity.

The National LambdaRail project is a separate Ethernet on Fiber (DWDM) network used by an association of research institutions.