OpenMath to MathML

>I am currently working on a project focusing on translating OpenMath to
>MathML and vice versa.
>I would be very interested in knowing if anyone has already worked on
>something similar, what was their approach and what were the general
>challenges encountered.

Dear Luis
Stephen Buswell has worked extensively on this problem under a European 
Commission project. Try visiting www.stilo.com for details of his
"MathWriter" development. I am from the same company.
With regards, 
Roy Pike