The different senses of the term _information_ in physical, biological, and social interpretations, and the possibility of connections between them, are addressed. Special attention is paid to Hofkirchner's Unified Theory of Information (UTI), proposing an integrated view in which the notion of information gets additional properties as one moves from the physical to the biological and the social realms. UTI is compared to other views of information, especially to two theories complementing several ideas of UTI: the theory of the hypertextual (...) documental universe ("docuverse") and the theory of integrative levels of reality. Two alternative applications of the complex of these three theories are discussed: a pragmatical, hermeneutic one, and a more ambitious realist, ontological one. The latter can be extended until considering information ("bit") together with matter-energy ("it") as a fundamental element in the world. Problems and opportunities with each view are discussed. It is found that the common ground for all three theories is an evolutionary approach, paying attention to the phylogenetic connections between the different meanings of information. The paper builds on previously unnoticed affinities between different families of information-related theories, showing how each of them can provide fruitful complements to the other ones in clarifying the nature of information. (shrink)