  Quantum resource theory is perhaps the most revolutionary framework that
quantum physics has ever experienced. It plays vigorous roles in unifying the
quantification methods of a requisite quantum effect as wells as in identifying
protocols that optimize its usefulness in a given application in areas ranging
from quantum information to computation. Moreover, the resource theories have
transmuted radical quantum phenomena like coherence, nonclassicality and
entanglement from being just intriguing to being helpful in executing realistic
thoughts. A general quantum resource theoretical framework relies on the method
of categorization of all possible quantum states into two sets, namely, the
free set and the resource set. Associated with the set of free states there is
a number of free quantum operations emerging from the natural constraints
attributed to the corresponding physical system. Then, the task of quantum
resource theory is to discover possible aspects arising from the restricted set
of operations as resources. Along with the rapid growth of various resource
theories corresponding to standard harmonic oscillator quantum optical states,
significant advancement has been expedited along the same direction for
generalized quantum optical states. Generalized quantum optical framework
strives to bring in several prosperous contemporary ideas including
nonlinearity, $\mathcal{PT}$-symmetric non-Hermitian theories, $q$-deformed
bosonic systems, etc., to accomplish similar but elevated objectives of the
standard quantum optics and information theories. In this article, we review
the developments of nonclassical resource theories of different generalized
quantum optical states and their usefulness in the context of quantum
information theories.
