Since the early stage of the polyolefins development, properties have been expanded by improving catalyst chemistry, morphology and by conducting polymerization in two successive steps, generating in each step a different polymer in ten-ns of molecular weight, crystallinity, composition to match the designed properties balance. Typical examples are heterophasic PP copolymers and broad MWD polyethylene. The two step technology has the typical limitation related to the final polymer unhomogeneity related to difficulty of achieving a good phase distribution when in synthesis too large domains of different materials are generated. Recently a new technology concept, the multizone circulating reactor has conceptually and practically moved to a higher level the phase distribution, the homogeneity and therefore the properties. Through this new principle, the growing polymeric granule is kept continuously circulating between two interrelated zones, where two distinct and different fluodynamic regimes are realized. In the first zone, the polymer is kept in a "fast fluidization"; leaving said zone, the transport gas is separated and the polymer crosses the second zone in the "packed bed mode" and is then reintroduced in the first zone. A complete and massive circulating is obtained between the two zones, managed by pressure balance. The fluodynamic. peculiar regime of the second zone, where the polymer enters as dense phase in "plug flow", offers the opportunity to alter, through simple but substantial means, the monomeric composition with respect to the chain terminator (hydrogen) and to the comonomer. Whenever required, by the same route and on the same growing granule, a multiple, alternate and cyclic as well as continuous polymerization can be obtained which attains the most complete and intimate mixing of different polymers, giving a substantial "homogeneity" of the final polymer. With a proper dimensioning of the two zones, it is thus possible to get a broad polymer molecular weight distribution, even starting from a catalyst able to develop only a limited molecular weight distribution. Moreover, intimate mixing of polymers that are different and even mutually incompatible is obtained, not only because they have grown in the same granule but also because the polymers are generated through short cyclic steps.