Binary Black Hole Grand Challenge Alliance

The Binary Black Hole Grand Challenge Alliance (BBH Challenge Alliance) was a scientific collaboration of international physics institutes and research groups dedicated to simulating the sources and predicting the waveforms for gravitational waves, in anticipation of gravitational radiation experiments such as LIGO.

History
The BBH Challenge Alliance was established in 1993. This was an alliance of numerical relativity groups engaged in a friendly competition to tackle the grand challenge of simulating binary black hole collisions for the purpose of understanding gravitational wave signatures that would be detected by experiments such as LIGO.