The simulation community has been accused for producing many simulation studies of bad quality. The mission of the oProbe open source project is to provide an instrument that produces statistically sound results at known quality. Stochastic sampling from a network of queues demands both confidence and correlation control. An important design goal is to be compatible with the OMNeT++ framework without introducing changes to this code, as well as making it easy for existing simulators to make use of oProbe. The oProbe project introduces a probe module, which is a new simple module in the context of OMNeT++. A probe is the instrument that applies a controlled stochastic sampling technique. The probe module may have any number of probes. The oProbe project supports different interface levels according to the functionality required. Based on the FIFO queue example included in the sample directory in OMNeT++, the oProbe project provides example code on how the software can be used by existing or upcoming OMNeT++ based simulators. [manual], [download]