From coherent sheaves to curves in {\bf P}^3

This paper is the text of a lecture given at the Catania conference on Commutative Algebra and Algebraic Geometry, in honor of the 60th birthday of Silvio Greco. It analyses the correspondences between equivalence classes of objects related to the projective 3-space ${\bf P}^3_k$ over a field $k$ : - vector bundles ${\cal F}$ such that $H_*^2({\cal F})=0$ up to stable equivalence - coherent sheaves of projective dimension $\leq 1$ up to pseudo-equivalence - finite length graded $k[X,Y,Z,T]$-modules, modulo isomorphism - biliaison classes of locally Cohen-Macaulay curves. In particular, it leads to the natural question : ``If a biliaison class contains subcanonical curves, is a minimal curve subcanonical ?'' for which a positive answer was given in math.AG/0102222.