Following from the MOST meeting in Vienna, I released an early alpha version of MOSTValidator v3.0. There is nothing to download as it is now a web service.
Please access it here: http://most.oracology.net/sandbox/validator.cgi
Warning! This software is an alpha release. It may (and probably will) contain bugs.
Having said that, the core MOSTValidator module was translated directly and should be bug-free.