Cloud Computing (CC) has attracted a massive amount of research and investment in the previous decade. The economical model proposed by this technology is a viable solution for consumers as well as being a profitable one for the provider. However, deploying real world cloud experiments to test new policies/algorithms is time consuming and very expensive, especially for large scenarios. As a result, the research community has opted to test their contributions is CC simulators. Although the models proposed by these simulators are not exhaustive, each one is made to address a specific process. Alternatively, others tools are made to provide a platform and the necessary building blocks to model any desired sub-component (application/network model, energy consumption, scheduling and Virtual Machine provisioning). In this paper, a detailed survey about the existing CC simulators is made discussing features, software architecture as well as the ingenuity behind these frameworks.