  Software testing is an important issue in software development process to
ensure higher quality on the products. Formal methods has been promising on
testing reactive systems, specially critical systems, where accuracy is
mandatory since any fault can cause severe damage. Systems of this nature are
characterized by receiving messages from the environment and producing outputs
in response. One of the most challenges in model-based testing is the
conformance checking of asynchronous reactive systems. The aim is to verify if
an implementation is in compliance with its respective specification. In this
work, we develop a practical tool to check conformance relation between
reactive models using a more general theory based on regular languages. The
approach, in fact, subsumes the classical \ioco conformance which is also
available in our tool. In addition, we present some studies with different
sceneries that are applied to practical tools with both notions of conformance.
