These Principles and Guidelines were produced by the Conference of European Statisticians Sharing Advisory Board and the UNECE Secretariat, with input and peer review from Participants in the 2011 joint UNECE / Eurostat / OECD meeting on Management of Statistical Information Systems (MSIS). This version was published right now, in February 2012.
The purposes of these guidelines are to provide a review some of the common best practices to develop internationalised software, to highlight some of the common standards in the area and to focus on topics that may specifically apply to statistical software such as the treatment of numbers, formatting, dates, formula treatment, and notation.
Guidelines are completed by a rich “Resources” paragraph with many links to Guides, Standards and other documents on the subject.
I’d like to add that the same principles apply to any software that has the need to address a multilingual environment, i.e. today every software on the Web .