The increasing use of the Web as a software platform together with the advance of technology has promoted Web applications as a starting point for improving communication between citizens and administration. Currently, several e-government Web portals propose applications for accessing information regarding healthcare, taxation, registration, housing, agriculture, education, and social services, which otherwise may be difficult to obtain. However, the adoption of services provided to citizens depends upon how such applications comply with the users' needs. Unfortunately, building an e-government website doesn't guarantee that all citizens who come to use it can access its contents. These services need to be accessible to all citizens/customers equally to ensure wider reach and subsequent adoption of the e-government services. User disabilities, computer or language illiteracy (e.g., foreign language), flexibility on information access (e.g., user remotely located in rural areas, homeless, mobile users), and ensuring user privacy on sensitive data are some of the barriers that must be taken into account when designing the User Interface (UI) of e-government applications. Although several initiatives (such as the W3C WAI) focus on how to promote usability and accessibility of content provided via e-government, many governments are enhancing their technology to make their services compatible with new communication channels available through multiple devices including interactive digital TVs (iTV), personal digital assistants (PDAs), and mobile phones. In this chapter we focus on this latter issue, which means the development of multitarget government services available across several platforms. Hereafter we discuss the major constraints underlining the importance of investment on the UI's design of e-government applications. Moreover, we propose a framework for envisioning advanced UIs where the adaptation to the user's capabilities and available devices as well as physical and social environment will play a major role.