Over the past few years there have been a number of efforts to build a XML-based format for gene expression data, include GeneXML[53] from the GeneX project and the MicroArray Markup Language (MAML) from MGED. Most recently, a joint effort from the creators of GeneXML and MAML together with a number of commercial organizations have developed the MicroArray Gene Expression Markup Language (MAGE-ML)[54,55] as a specification for the Object Management Group.