We are proud to present the TAMODIA 2006 proceedings. In 2006, the TA- MODIA workshop celebrated its ?fth anniversary. TAMODIA is an obscure acronym that stands for TAsk MOdels and DIAgrams for user interface - sign. The ?rst edition of TAMODIA was organized in Bucharest (Romania) by Costin Pribeanu and Jean Vanderdonckt. The fact that ?ve years later the TAMODIAseriesofworkshopsstillcontinuessuccessfullyprovestheimportance of this research area for the human–computer interaction community! The ?rst workshopaimed at examining how multiple forms of task expressionscan sign- icantly increase or decrease the quality of user interface design. This is still the scope of the current edition; we tried to assemble papers that discuss how the complexity of HCI design and development can be managed with tasks, models and diagrams. Much like the previous editions, the selection of papers from the 2006 edition re?ects the broad scope of this ?eld, which cannot be labeled with a single title or term. The invited paper is by Jo¨ elle Coutaz and discusses meta-user interfaces for ambient spaces. Finding appropriate ways to design and develop user interfaces for interactive spaces is becoming an important challenge for the creation of future usable applications. This exciting work gives a good feel of the new type of user interfaces and the required new approaches we are evolving toward when we want to realize the vision of ambient intelligent environments and create systems that can be used and controlled by the end-users.