Numerical Analysis

Foundations of Computational Mathematics (FoCM) - A nonprofit organization that supports and promotes research on foundations of computational mathematics.
http://www.focm.net/

MGNet - Multigrid method resources. Sites, publications, software.
http://casper.cs.yale.edu/mgnet/www/mgnet.html

Tomasz Plewa's Numerical Analysis Directory - Directory of sites containing software for numerical analysis (mainly in Fortran).
http://www.labyrinth.net.au/~ctrans/tomasz.html

Orthogonal Polynomials and Special Functions - SIAM activity group. Newsletter, conferences, bibliography, reports, history, jobs, other resources.
http://math.nist.gov/opsf/

N-Body/Particle Simulation Methods - Overview of N-body methods.
http://www.amara.com/papers/nbody.html

NA-Net - Searchable weekly email digest on numerical analysis.
http://www.netlib.org/na-net/na_home.html

Numerical Methods - A guide to on-line resources.
http://tonic.physics.sunysb.edu/docs/num_meth.html

Domain Decomposition Organization - Bergen, Norway. Information about the annual international Domain Decomposition meeting, links to people working in the field and information about books and other material related to Domain Decomposition.
http://www.ddm.org/

IPNet - Inverse Problems Network, for the area of inverse or ill-posed problems.
http://www.mth.msu.edu/ipnet/

On-line Numerical Methods - A web-based numerical methods simulator for student use.
http://mn.fe.up.pt/second_en.htm

Numerical Methods for PDEs with Java Applets - Distance learning course dealing with finite differences / elements, Monte-Carlo, Fourier and Lagrangian methods for the advection, diffusion, wave, Schrodinger, Burger and KdV equations. The commercial version of a course taught to science and engineering students at the Royal Institute of Technology in Stockholm (Sweden).
http://www.lifelong-learners.com/pde

Solve Equations by Successive Approximations - Approximation formulae to compute real and complex solutions of equations in a spreadsheet.
http://members.aceweb.com/patrussell/approximations/introduction.htm

Holistic Numerical Methods Institute - A collection of resources on numerical methods aimed at undergraduates, maintained at the University of South Florida.
http://numericalmethods.eng.usf.edu

External Numerical Analysis Sources - Compiled by Nick Gould, Rutherford Appleton Laboratory.
http://www.numerical.rl.ac.uk/external/external.html

Inverse Symbolic Calculator - Programs and specialized tables of mathematical constants dedicated to the identification of real numbers: a project at the Centre for Experimental and Constructive Mathematics.
http://oldweb.cecm.sfu.ca/projects/ISC/

Newton's Method and High-order Iterations - Newton's iteration : History, convergence results, Halley's iteration and high order new iterations. A web text in HTML and PostScript.
http://numbers.computation.free.fr/Constants/Algorithms/newton.html

SQRT - Algorithms for Calculating the Square Root - Describing two major algorithms: one efficient in terms of size, the other in terms of speed. English/Portuguese.
http://www.pedrofreire.com/sqrt/

Interval Computations - Indexes links relating to interval arithmetic and related issues.
http://www.cs.utep.edu/interval-comp/

Level Set and Fast Marching Methods: - Tracking moving interfaces in computational geometry, materials sciences, robotics, image processing, and fluid mechanics; numerical techniques based on partial differential equations.
http://www.math.berkeley.edu/~sethian