A few years ago, Listos (known as Listarchos Devious in SWG) and his friend Shados created a Sith language for their roleplay characters. The language was amazingly complete. Lisandra created a automatic translator for the basic words from the list. That was created in 2009.
On January 2nd and 3rd, Listos and I updated the list of words. The list now includes the canon Sith words as well as some additional words. I hope you enjoy it.