A group of Bantu languages in Southern Africa including:
These are close enough that this apparently facilites some translation and localisation work. They may also be close enough for "shallow transfer" machine translation programs like Apertium.
The close relationship among the Nguni languages facilitates some aspects of localisation [need more info here!]
It also may be useful to approach machine translation among these tongues with a "shallow" transfer method such as used by the "Apertium" open source package. [more info?]
An April 2005 note on the LDL site at http://www.ecml.at/mtp2/LDL/html/LDL_E_news.htm references an approach to publication in "Nguni":
"Another exciting development concerns the publication in the Nguni languages of Madiba Magic, a collection of traditional stories selected by Nelson Mandela. Instead of following the more usual course of publishing separate single language versions such as Zulu and Xhosa, this book includes a range of related language varieties. The effect of this decision is to underline commonalities rather than differences between speakers. This initiative has resonances with an existing European publication, produced by another LDL team member and her colleagues, which includes authentic texts in the languages spoken in Bosnia and Herzegovina."