The paper surveys recent results obtained for the existence and multiplicity of radial solutions of Dirichlet problems of the type ∇ · ( ∇v ⁄ √ 1 − |∇v| 2 ) = f(|x|, v) in BR, u = 0 on ∂BR, where BR is the open ball of center 0 and radius R in R n , and f is continuous. Comparison is made with similar results for the Laplacian. Topological and variational methods are used and the case of positive solutions is emphasized. The paper ends with the case of a general domain.