Software agents usually operate in dynamic, unpredictable environments with many unforeseen features that change over time. In order to be effective an agent has to adapt itself to the changes in its environment. In this paper we present AJA, an agent development tool that can be used for the development of adaptable agents implemented in Java. In addition to adaptability, AJA agents possess other attractive features as well, such as negotiation capability realized using conversation scenarios, reactivity to events in the agent environment, meta-capability, accessibility via World Wide Web (WWW), etc.