So it turns out that many medieval Rabbanites from the Land of Israel and the surrounding environs deserve a badge of interdenominational awesomeness as well.
And traces of this awesomeness run from Cairo in the early 11th century all the way to the Rabbanites of Egypt in the years following the birth of the State of Israel. Again, don’t take my word for it.
The oldest (known) complete copy of the Hebrew Bible surviving today is the Leningrad Codex, which is widely regarded as the second most important text in the Jewish biblical tradition. The Leningrad Codex was written in the year 1008 (or 1009), most likely in Cairo.
I had always thought that the Leningrad Codex was a Karaite manuscript; but over the last few weeks, I’ve increasingly come to believe that the Leningrad Codex was, in fact, a Rabbanite manuscript. 
What is remarkable about the Leningrad Codex is that the entire text (consonants, vowels, and masoretic notes) were the work of one man: Samuel ben Jacob. The Aleppo Codex, by contrast, was the work of two individuals (both Karaites): Shlomo ben Buya’a and Aaron ben Asher.
As if that were not awesome enough, the 11th century Rabbanites, like their Karaite counterparts, also supported members of opposing groups. A handful of Karaites “distinguished as such” appear on the “[c]harity lists drawn up the by the Palestinian Rabbanite community in Fustat . . . as recipients of food and money.” 
But in perhaps the hardest-to-believe display of open-mindedness, in the ninth century, descendents of Anan ben David (who is often considered the founder of modern Karaism) headed the famous Rabbanite yeshiva in Tiberias. WHAT!?! 
And in the 1950s, when the Aliyah Department of the Jewish Agency was pressured to cease Karaite aliyah from Egypt, Orthodox Egyptian Rabbanites halted all Egyptian aliyah activity for one month in 1950, “until instructions were received permitting Karaites to come to Israel.” 
Rami Mangoubi, an Egyptian Karaite Jew, first learned of this incident in France while under the care of a refugee organization after fleeing Egypt. Years later, in 1979, Mr. Mangoubi happened to meet some Egyptian Rabbanites in Israel, and they started exchanging memories of Egypt. According to one of these Egyptian Rabbanites, the organizers of aliyah activities in Egypt made sure that the restriction on Karaite aliyah remain unbeknownst to the general community, “parce que c’est une honte, nous sommes des freres” (“because it is a shame, we are brothers”).
That display of unity is truly awesome. And if descendents of Anan ben David could become head of the Rabbanite yeshiva in Tiberias, maybe one day a Karaite can head the Rabbanut.
* * *
 Perhaps, I’ll detail in a different post why the Leningrad Codex is believed to be a Rabbanite manuscript.
 See Rustow, Heresy and the Politics of Community: Jews of the Fatimid Caliphate, p. 256.
 See Gil, A History of Palestine: 634-1099, p. 658; see also Rustow, Heresy and the Politics of Community: Jews of the Fatimid Caliphate, pp. 33-34.
 See Beinin, The Dispersion of Egyptian Jewry, pp. 183-184.