Section 8.1 highlights variational objects of general bifunctions and solutions of quasiequilibrium problems, since they are different from the special case in Chap. 8 . Section 8.2 contains characterizations and variational properties of the types of variational convergence following the same line as in Sects. 7.1 and 7.2 in order to shorten the presentation, including comparisons. Section 8.3 discusses the recent topic of quantification of variational convergence of bifunctions. In Sect. 8.4, the convergence results for approximate solutions of quasiequilibrium problems are obtained in a brief presentation, including a highlight of the differences from the case in Sect. 7.3 . Then, the new topic of quantitative approximations of quasiequilibrium problems is studied by combining the above convergence results and the quantification of variational convergence of bifunctions. Approximations of the Nash game (also called generalized noncooperative game) both in terms of variational convergence of the Nikaido-Isoda bifunction of the game and directly in terms of its data are considered in Sect. 8.5. Section 8.6 provides very recent results on approximations of set-valued quasivariational inequalities, which constitute an important particular case of quasiequilibrium problems, and applications to a modern model of traffic networks. Section 8.7 deals with optimization problems under stochastic ambiguity with a focus on their distribution-based formulations. Examples of such formulations and applications of lop convergence in practical problems are provided.