For the agile software development community, agility is defined by the values expressed in the agile manifesto. But in concrete terms, what does it mean for a software project to be agile? US Air Force Colonel John Boyd defined agility as the ability to operate the Observation-Orientation-Decision-Action (OODA) loop faster than an adversary. Agility therefore depends on the tempo at which we can exploit the OODA loop, and it is culture, not methodologies or tools that determine our OODA loop speed. This definition of agility has implications for the software development community. This short paper introduces Colonel Boyd, the OODA loop, the factors which influence OODA loop speed and the possible research opportunities into software engineering culture we are considering.