Intermediate representations (IR) are a key issue both for compilers as well as for reverse engineering tools to enable efficient analyses. Research in the field of compilers has proposed many sophisticated IRs that can be used in the domain of reverse engineering, especially in the case of deep analyses, but reverse engineering has also its own requirements for intermediate representations not covered by traditional compiler technology. This paper discusses requirements of IRs for reverse engineering. It shows then how most of these requirements can be met by extending and integrating existing IRs. These extensions include a generalized AST and a mechanism supporting multiple views on programs. Moreover, the paper shows how these views can efficiently be implemented.