In this paper, network-based cooperative control of nonlinear dynamical systems is investigated. A theorem on cooperative stability is presented for designing nonlinear consensus algorithms, the proposed design admits varying topologies of network information flow as well as latencies in data transmission, and the network condition for achieving consensus is shown to be the same as in cooperative control of linear systems. A nonlinear triple-integrator example is used to illustrate the proposed nonlinear design and also to show how other design procedures such as the recursive design can be utilized to facilitate the design of cooperative control. In addition to network uncertainties, unknowns and/or uncertainties in dynamics of heterogeneous nonlinear systems are also considered. It is shown that both adaptive and robust control methodologies can be integrated into the proposed design in order to handle unknown/uncertain systems sharing a varying information network.