The R Project SVN R

bs      Generate a Basis for Polynomial Splines 
ns      Generate a Basis Matrix for Natural Cubic Splines 
predict.bs  Evaluate a predefined spline basis at new values
predict.ns  Evaluate a predefined spline basis at new values
splineDesign    Create the design matrix for a collection of B-splines
interpSpline    Determine the natural interpolation spline
periodicSpline  Determine a periodic interpolation spline
polySpline  Construct the piecewise polynomial representation of a spline
splineKnots Extract the knot positions from a spline object
splineOrder Extract the spline order from a spline object