In this paper, we introduce input adaptability as the ability of an application to exploit alternative sets of input devices effectively and offer users a way of adapting input interaction to suit their needs. We explain why input adaptability must be seriously considered today and show how it is poorly supported by current systems, applications and tools. We then describe ICon (Input Configurator), an input toolkit that allows interactive applications to achieve a high level of input adaptability. We present the software architecture behind ICon then the toolkit itself, and give several examples of non-standard interaction techniques that are easy to build and modify using ICon's graphical editor while being hard or impossible to support using regular GUI toolkits.