Smoothing splines
Fortran 90 routines by Ian Enting for calculating smoothing splines and propagating data uncertainties to obtain uncertainty ranges for the spline fits.
http://www.ms.unimelb.edu.au/~enting/spline.html

Smoothing Splines
RKPACK and RKPACK-II are collections of RATFOR (rational FORTRAN) routines by Chong Gu for Gaussian regression using smoothing splines, penalized likelihood density and hazard estimation.
http://www.stat.purdue.edu/~chong/software.html

Master Flo Valve Inc.
Master Flo Valve is a technological leader and world-class manufacturer of chokes, specialty control valves and supporting actuation. Master Flo manufactures high-quality products supported by innovative engineering and outstanding quality assurance.
http://www.masterflo.com

GCV
Fortran 77 and RATFOR code to fit smoothing splines using generalized cross-validation.
http://www.netlib.org/gcv/index.html

Abramovich, Felix
Shrinkage, nonparametric regression, smoothing methods, inverse problems.
http://www.math.tau.ac.il/~felix/

DIERCKX
Fortran subroutines for calculating smoothing splines for various kinds of data and geometries, with automatic knot selection.
http://www.netlib.org/dierckx/index.html

Kalman smoothing routine for Hodrick-Prescott filter
By E. Prescott.
http://dge.repec.org/codes/hpfilter.for

Laybond Products Ltd
Flooring and tiling products for the professional, marketed under the brands of Laybond, Biscem, Technik, Bostik and Evo-Sport.
http://www.laybond.co.uk

Maximum Entropy Modeling Toolkit
A library of tools for constructing maximum entropy (maxent) model in either python or C++. Some program features are L-BFGS and GIS parameter estimation, and gaussian prior smoothing. [GPL]
http://homepages.inf.ed.ac.uk/s0450736/maxent_toolkit.html

ACT
A manufacturer of inductors, EMI suppressors, chokes, coils and transformers.
http://www.act1.com/