After many years of hypertext research, the Dexter model was defined [7] to capture the features of most existing hypertext systems in a single, formal reference model. Likewise, the AHAM model
[5] (based on Dexter) describes most features that are found in adaptive hypermedia systems (ahs). In the AHA! project funded
by the NLnet Foundation we are extending the simple AHA system [4], [6] with the condition-action rules that were introduced in AHAM [8]. This results in a more versatile adaptation engine, with more intuitive and more powerful rules.