jsMath
Tutorial: Computing With Modular Forms Using SAGE
Contents,
General,
Modular Forms,
Modular Symbols,
Future
To use SAGE effectively, it is critical that you 
know about 
-  The SAGE documentation (a tutorial, reference manual, etc.)
-  In the notebook click "Documentation" in the upper right for a live version.
-  SAGE uses the Python language, which is simple and clean: In 
Python indentation matters !!.  But there is no need for semicolons, begins, ends, braces, etc. 
-  If foo is a function, 
use foo? to get help on foo; use foo?? to see the source code.
-  If obj is an object, type obj.[tab key] to see what you can do with obj. 
-  SAGE is a GPL'd open source software project I started in 2005
that has about 50 developers worldwide, and includes and builds
on GP/PARI, Gap, Singular, and Maxima.  The goal is to provide
a viable open source alternative to Magma, Maple, Matlab, and Mathematica -- i.e.,
it's not just for arithmetic geometry -- though arithmetic geometry tends to
use most other areas of math at some point...