Jews of different geographic/ethnic communities each have their own prayerbook, often referred to as a nusach
(pattern, formula). These prayerbooks are identical in many fundamental prayers, but feature local variations in piyyutim
(post-Talmudic poetic prayers), order, and minhag
(customary ways to worship). Thus, there is a Nusach Ashkenazi
(Central European pattern) and a Nusach Sefardi
(Spanish/Portuguese pattern). Jews who descend from these communities are expected to loyally hold to the nusach/minhag of their ancestors, though in practice Jews may switch because of marriage into a family of different roots, or because of relocating to a community where their minhag is not observed.
It was therefore a great scandal to many Jews of Eastern Europe when the newly forming Hasidic communities abandoned the Ashkenazi prayerbook in favor of the prayerbook Nusach ha-Ari (The Lurianic Siddur), a prayerbook that fused Sefardi elements with mystical kavvanot (meditations/intentions). This siddur is a attributed to Isaac Luria, also known as ha-Ari ha-Kodesh (the Holy Lion), a kabbalist of mixed background himself, coming from an Ashkenazi family that had settled in Egypt. In fact, the Nusach ha-Ari was mostly the creation of his followers in the Middle East.
But this prayerbook crossed ethnic boundaries and soon found its way into the Ukraine, Poland, and Russia. The Maggid of Meseritch, for example, noted that according to the Midrash, each of the twelve tribes had their own gate in heaven through which their prayers entered, yet there was a thirteenth gate by which the prayers of anybody could be heard On High, and he argued the Nusach ha-Ari was that 13th gate . Many variations of the Nusach ha-Ari eventually appeared over time, including the prayerbooks Siddur Shar'abi, Kol Yaakov, Siddur Torah Ohr, and Siddur Tehillat Hashem. Not surprisingly, some of these were revisions to more closely follow the European minhag. Many were also streamlined. Early versions had elaborate meditations punctuating the prayers and even featured the texts configured in symbolic patterns or arranged so as to form recognizable objects, such as faces or humanoid figures . Latter varieties, dense as they might be with commentaries and insertions, were more conventional and less imaginative in their layouts. Zal G'mor:
To learn more, consult the Encyclopedia of Jewish Myth, Magic, and Mysticism - http://www.amazon.com/Encyclopedia-Jewish-Myth-Magic-Mysticism/dp/0738709050
 Jacobs, Hasidic Prayer, p. 38.
 Blumenthal, Understanding Jewish Mysticism, p. 173.