Do you know any open source tools or libraries (preferably Java, but that\'s not a strict requirement) in the GNU/Linux world that convert mathematical equations in LaTeX syntax
This might be what you are looking for: SnuggleTeX
From the site:
SnuggleTeX is a 100% Java library for converting (a reasonable subset of) LaTeX into XHTML + MathML.
SnuggleTeX can attempt to convert input LaTeX to Content MathML by first creating Enhanced Presentation MathML and then processing that. In many ways, this part of the process is relatively simple since most of the semantic structure has already been inferred (though might not necessarily make any sense).
You can also use an online equation editor WIRIS editor which is able to import MathML/Latex and export to MathML/Latex
You may want to have a look at LaTeXML. It converts LaTeX to various XML formats, including OpenMath and content MathML.
But be warned, like all other tools, the conversion from (presentation-oriented) LaTeX to content markup (as in OpenMath and MathML) is heuristic. In particular, in ambiguous situations (e.g. $f(a+b)$, which can mean $f$ applied to $(a+b)$ or $f$ times $(a+b)$) LaTeXML chooses one (usually times).
There are two ways out:
1) use content markup already in the LaTeX source (see http://trac.kwarc.info/sTeX)
2) use a better post-processor for LaTeXML is working on this
Have a look over here, where you can find a perl version.