While my question applies to Jenkins (software) which was named after Jenkins named meant to evoke a feel of English butler, there is a historical precent:
http://en.wikipedia.org/wiki/War_of_Jenkins'_Ear
Wikipedia article has Jenkins' in the title and Jenkins's in reference to historical book.
However modern grammar rules seem to imply that correct possessive form in modern English would be Jenkins'es.
So what is correct? Or are several options acceptable?
a. The Hughes' home (or the Hughes's home), Mr Jones's shop (or Mr Jones' shop), Charles' book (or Charles's book)' >> (Some people make a choice informed by whether they pronounce the extra syllable or not. Some even make this into a rule. // If a city / organisation decides on one form they want to be used, that is a rule.)
– Edwin Ashworth Sep 02 '14 at 14:49