The use of modelling abstractions to map from items in the real-world to objects in the computational domain is useful both for the effective implementation of abstract problem solutions and for the management of software complexity. This paper discusses the new approach of agent-oriented software engineering (AOSE), which uses the notion of an autonomous agent as its fundamental modelling abstraction. For the AOSE approach to be fully exploited, software engineers must be able to gain leverage from an agent software architecture and framework, and there are several such frameworks now publicly available. At the present time however there is little information concerning the options that are available and what needs to be considered when choosing or developing an agent framework. We consider three different agent software architectures that are (or will be) publicly available and evaluate some of the design and architectural differences and trade-offs that are associated with them and their impact on agent-oriented software development. Our discussion examines these frameworks in the context of an example in the area of distributed information systems.