In this paper we present NekoStat, an extension of the Neko tool. Neko is a Java framework and a communication platform that permits rapid prototyping of distributed applications; it provides tools to organize the applications using a layered architecture, with the network(s) at the bottom of the architecture. Neko is also a communication platform that allows sending and receiving of generic Java objects. Distributed systems realized within the Neko framework can be exercised both on real networks and on simulated ones, without changes in the application code. We constructed an extension to plain Neko, called NekoStat; it permits attainment of quantitative evaluations of distributed systems. In the paper we describe this extension; we motivate the development of NekoStat, we describe the design and finally we illustrate its usage through a case study, which highlights the usefulness of NekoStat.