Information on the Web is rapidly growing, and mathematical topics are no exception.
    But, information was mostly static. Some mechanism to add interactive features are 
    
      
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          |  | CGI Scripts |  | special access required | 
      
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          |  | Hyperlink to, say, Maple |  | software package required | 
      
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          |  | Plugins |  | download and updating required | 
      
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          |  |  |  | 
          |  | everybody can do it |  |  | no installation required |  |  | runs on any platform |  |  | Java tools available for free |  |