We introduce and study noncommutative (or "quantized") versions of the algebras of holomorphic functions on the polydisk and on the ball in C n . Specifically, for each q ∈ C × = C \ {0} we construct Fréchet algebras O q (D n ) and O q (B n ) such that for q = 1 they are isomorphic to the algebras of holomorphic functions on the open polydisk D n and on the open ball B n , respectively. We show that O q (D n ) and O q (B n ) are not isomorphic provided that |q| = 1 and n ≥ 2. This result can be interpreted as a q-analog of Poincaré's theorem, which asserts that D n and B n are not biholomorphically equivalent unless n = 1. In contrast, O q (D n ) and O q (B n ) are shown to be isomorphic for |q| = 1. Next we prove that O q (D n ) is isomorphic to a quotient of J. L. Taylor's "free polydisk algebra" (1972). This enables us to construct a Fréchet O(C × )-algebra O def (D n ) whose "fiber" over each q ∈ C × is isomorphic to O q (D n ). Replacing the free polydisk algebra by G. Popescu's "free ball algebra" (2006)respectively. Finally, we study relations between our deformations and formal deformations of O(D n ) and O(B n ). ]. Some parallels between Taylor's theory and the "operator algebraic" noncommutative complex analysis are discussed in [68, 94, 95]. A related approach going back to Taylor's notion of an Arens-Michael envelope [160] was developed by A. A. Dosi (Dosiev) [42-46] and the author [104-106, 109, 110]. A more algebraic view of noncommutative complex geometry is based on A. Connes' fundamental ideas [32,33]. The notion of connection introduced by Connes in [32] was used by A. Schwarz [146] to define complex structures on noncommutative tori. This line of research was further developed by M. Dieng and A. Schwarz [41] and by A. Polishchuk and A. Schwarz [112-114]. A closely related point of view was adopted by J. Rosenberg [145], M. Khalkhali, G. Landi, W. D. van Suijlekom, and A. Moatadelro [71-73], E. Beggs and S. P. Smith [13], R.Ó Buachalla [ [98][99][100]. Another approach was also initiated by Connes [33, Section VI.2], who interpreted complex structures on a compact 2-dimensional manifold M in terms of positive Hochschild cocycles on the algebra of smooth functions on M. Motivated by this, he suggested to use positivity in Hochschild cohomology as a starting point for developing noncommutative complex geometry. This point of view was developed by M. Khalkhali, G. Landi, W. D. van Suijlekom, and A. Moatadelro [loc. cit.], who found relations between complex structures on noncommutative projective spaces and twisted positive Hochschild cocycles on suitable quantized function algebras. A common feature of the above papers is that almost all concrete "noncommutative complex manifolds" that appear therein are compact. Thus section spaces of "noncommutative holomorphic bundles" over such "manifolds" are finite-dimensional, and so no functional analysis is needed for their study. We refer to [71] and [13] for a detailed discussion of this side of noncommutative complex geometry.An enormous contributio...