An complexity singularity is a singularity that may form in complex systems. It requires an acceptance of multipathism (and therefore quantum mechanics).
In a complex system, an event may lead to a high number of outcomes. These outcomes may be more complicated than the original situation, and may trigger events that lead to even more outcomes. In the right conditions (ie the system does not break down), these possibilities may increase exponentially, leading to a singularity.
This may be equivalent to an intelligence singularity. This link might be aided by quantellism, which states that quantum effects are magnified by humans and kulti.