The current EVA architecture is the result of the project evolution rather than a single design thread. The initial version of EVA was developed as an application running on the Windows desktop environment, with most features “hard coded” in C++. The creature design was limited to a simple 3D face (left part of the image), inspired by Ken Perlin’s face demo project. The second version (2004) added a tiny Scheme interpreter for scripting the creature’s behaviors and Genetic Programming experiments (right part of the image shows an example of a 3D face in version 2). A description of this version has been published at the Intelligent Agent Technology conference in 2004. The third version (2006) was the first Java implementation of EVA. It introduced also the use of XML for coding knowledge bases. The fourth version (2007) provided a Multi-Agent architecture based on a small set of agents and a communication server. We conducted web mining experiments with this version. The last version (2008) is the most open and advanced architecture based on a swarm-like model.