Hyperloop is based on the idea of Elon Musk. He has released the project and it is developed by two companies Hyperloop Transportation Technologies (HTT) and Hyperloop Technologies now. Because of a significant similarity between these two names, Hyperloop Technologies was renamed to Hyperloop One. This company has successfully tested the prototype in Nevada desert.
This test was focused on the propulsion system on an open-air short testing track and the sled was able to achieve 400 MPH (640 km/h). This 1500 pounds (680 kg) weighing vehicle accelerated from 0 to 60 MPH (96 km/h) in just 1.1 seconds and the maximal acceleration was more than 2.5 G.
Hyperloop plans to carry out a quarter-mile test with a complete track (including the tubes). They also plan to test levitation system. Hyperloop expects that the final version of vehicle will be able to drive at 700 MPH.
Source: engadget.com, hyperloop-one.com