Intelligence, collaboration and mobility are the main important features in designing
agents for  electronic commercial systems. But very few systems permit to implement
agents which have all these characteristics. In this paper, we address the problems of
designing intelligent collaborative mobile agents. We propose a componential approach
for designing and implementing such agents. Our framework architecture for agents
decouples components expressing the internal behavior of an agent from components
expressing coordination between agents in order to enhance modularity and reusability.
Our agent design and implementation environment consists in three distinct phases :
modeling, validation and implementation. We have developed a component description
language for easy modeling of componential agent architecture. The component specification
is automatically translated into Java source code by our compiler, and then integrated into
a mobile agent platform. We have integrated our agent implementation environment into
two different mobile agent platforms, namely JNA (JavaNet Agent) and Voyager.
We have tested our agent development system with the Travel Agency scenario,
one of the standard electronic commercial service examples.