This article reviews various results on highest weight modules for Lie algebras and quantized enveloping algebras defined over a commutative ring. Such results include the formula for the Shapovalov determinant and Jantzen's character sum formula, which were extended to the quantum case by A. Joseph and G. Letzter \ref[Math. Z. 222 (1996), no. 4, 543--571 At the end of the article some joint work with T. J. Enright is discussed. This work, which involved localization and lifting of invariant forms, appeared in 1995 \ref[Comm. Algebra 23 (1995), no. 6, 2215--2254