The World Academy of Rusyn Culture has a good site on the language called Rusyn by its speakers and sometimes Ruthenian in English (or “western Ukrainian” by those who do not recognize it as a separate language):
The language territory where Carpatho-Rusyn dialects are spoken coincides with the historical territory of *Carpathian Rus’, which in terms of present-day boundaries is located within southeastern Poland (the *Lemko Region), northeastern Slovakia (the *Prešov Region), most of the *Transcarpathian oblast of Ukraine (*Subcarpathian Rus’), and a small corner of north-central Romania (the *Maramureş Region). Rusyn is also spoken in a few scattered communities in northeastern Hungary and among emigrants from Carpathian Rus’ who settled in the *Vojvodina and Srem regions of present-day Yugoslavia and far eastern Croatia and in the United States and Canada…
The difficulty in classifying Carpatho-Rusyn dialects stems largely from the fact that individual dialect territories experience an overlapping of numerous isoglosses. In other words, certain linguistic features typical of one area encroach into other areas; determining where to draw a boundary between these territories in the process of defining and classifying the dialects thus becomes difficult. Another difficulty in classification is related to the fact that the dialects have in the past and continue to be influenced by numerous sociolinguistic or extralinguistic factors from the larger world in which Rusyns live, whether in Ukraine, Slovakia, Poland, Romania, Hungary, Yugoslavia, the United States, or Canada. When attempting a synchronic description of the language system of dialects and in classifying them, researchers must consider the larger linguistic and cultural worlds in which dialects function. The structure and function of the dialects must be described in connection with the languages with which they are in contact.
A nice find by Christopher Culver, who also posts about a projected Indogermanische Grammatik that was begun in 1968 by Kuryłowicz, “was subsequently continued by Watkins, Cowgill, and Mayrhofer, and is nowhere near completion… I wonder what the oldest perpetually unfinished project is in Indo-European linguistics.” So which will appear first, this or The Last Dangerous Visions?