Ordinary Differential Equations on the web:

• Study Guide, by the Oregon State University
• ODE , by the Northern Illinois University
• Eric Wisstein's World Of Mathematics

Recent development of various computers, from the personal computer to the super computer, involves rapid change in computer architecture and advancement in software engineering. There is a proliferation of solvers which focus on differential equations, ranging from simple numeric solvers to very comprehensive computer algebra software solvers. These packages are very helpful in education, numerical simulation and applications of differential equations and more is being developed every day. This is not a complete and comprehensive listing, we pay attention to the most popular packages.

• IDEA Internet Differential Equations Activities
• CODEE, Consortium of ODE Experiments
  
• Links, A collection of links by Ted Scheick at UNC
  
• ACSL, Advanced Continuous Simulation Language
• Derive, by Soft Warehouse; now by Texas Instruments (see here)
• Hi-Q, for Macintosh and Sun computers
• Maxima is a descendant of DOE Macsyma, the oldest CAS for Unix/Linux
• Maple, by Maplesoft with applications to ODE
• Mathcad, by MathSoft
  
• Mathematica, by Wolfram
• Matlab, by MathWorks with DFIELD by John C. Polking
• MDEP, by Jim Buchanan
• MuPAD, by the MuPAD Research Group
• Octave, is freely redistributable software
• Phaser , by Huseyin Kocak
• Reduce, with ODESolve by Francis Wright

Other small packages:

• MathView by Waterloo Maple Inc.
• DEPAC, by L. F. Shampine and H.A. Watts
• SDRIV, contains three packages
  
• ODEPACK is a systemized package of routines
• MVT, (the Mathematical Visualization Toolkit) by the University of Colorado
• Winplot, by Richard Parris
• ODE Toolkit, nice Java application for ODEs