I've heard of pytroll:

http://www.pytroll.org/

Take a look at this page:

http://www.wmo.int/pages/prog/sat/processingtools_en.php

They're listing some processing tools for meteorological data.

I'm aware of zyGrib which is an open source grib viewer, maybe it has some plugins for xRIT format you could easily use.

Thanks!  I've heard of pytroll but i have not try it yet. The other link is very helpful .

Hi Miguel,

pytroll seems to be the most popular solution right now.

In any case, along with Jf suggestions and for completeness purposes, you might also want to check out "mipp":

http://mipp.readthedocs.org/en/latest/introduction.html

And the list from "Eumestat":

http://www.eumetsat.int/website/home/Data/DataDelivery/SupportSoftwareandTools/index.html

Thanks