Interiormethodsareanomnipresent,conspicuousfeatureoftheconstrainedoptimizationlandscapetoday,butitwasnotalwaysso.Primarilyintheformofbarriermethods,interior-pointtechniqueswerepopularduringthe1960sforsolvingnonlinearlyconstrainedproblems.However,theiruseforlinearprogrammingwasnotevencon