Résumé : We consider in this paper the simultaneous problem of optimal robust stabilization and optimal tracking for SISO systems in an $L^\infty$-setting using a two-parameter compensator scheme. Optimal robustness is linked to the work done by Georgiou and Smith in the $L^2$-setting. Optimal tracking involves the resolution of $L^1$-optimization problems. We consider in particular the robust control of delay systems. We determine explicit expressions of the Bezout factors for general delay systems which are in the Callier-Desoer class $\hat{\cal B}(0)$. Finally, we solve several general $L^1$-optimization problems and give an algorithm to solve the optimal robust control problem for a large class of delay systems.