[Om] conversion between formats

[Dima]

Hi,
  On openmath.org pages, e.g.

http://www.openmath.org/cd/calculus1.xhtml

mathematical expressions are notated in various representations simultaneously. Is there any libre and open source software that is used to convert (when possible) between Content MathML , Representation MathML, OpenMath and Prefix notation for generation of these pages?

  (Popcorn has web page for itself). Generally, which (libre and open source) software could you recommend for notation conversion ?

Thanks, regards,
  Dima.