So-called holocaust "revisionists" are, of course, in reality holocaust deniers, who do it in order to make murderous antisemitism socially acceptable again. They also trot out the same old "Jews control the world" antisemitic conspiracy theories, but, for the same reason of shooting for social acceptance, re-name them "zionists" or "international bankers" or similar cover names.
The ironic thing is that there are tons of real holocaust revisionists. They are known as "historians". Historians hotly debate, for instance, if the holocaust really was planned in some form since the 1920s or a result of the war in the east in the early 1940s. Historians debate if really six million were killed -- some say it was "only" about 5,100,000 million or so, some that it is up to 6,700,000. Historians exploded the myth of the "lamps made of human skin" or "soap made of human fat" as -- horrific as they were -- at most isolated experiments. Historians noted that the USSR's claim that "four million soviet citizens" were killed in Auschwitz is not true, and that Hoess bragging about killing two million was an exagerration. (Yes, the -- roughly -- 6 million Jewish dead are computed *after* discounting these exagerrations.) Historians note that there were many millions of non-Jewish victims: for example, "Nizkor"'s web site is dedicated to the "12 million victims" of Nazi camps and massacres, about 6 million Jews and 6 million non-Jews. Historians even note that the Nuremberg trials, while certainly light-years away from anything the Nazis would have given a vanquished enemy, were nevertheless (unavoidably) victor's justice, and in some cases the judges, being human, probably erred: e.g., some (Streicher) were hanged more due to their loathsome personality than due to anything they did that formally violated the indictment's counts, while others (Speer) got off lightly because they were of the upper class, young and handsome.
Now, NONE of this fits the "Hitler planned to make all the Jews into soap from the 1920s and gassed six million of the in Auschwitz, until perfect justice reached them in Nuremberg" story some of us heard as children, or even in school. Yet NONE of the historians who "doubted the official story" -- the caricature I just quoted -- were ever called holocaust deniers by any serious person. Why? Because this sort of historical revisionism, checking the accepted story of the past based on evidence, is what historians DO.
This is 100% different than what the deniers, who wrongly call themselves "revisionists", do. They "know" the holocaust is all a "zionist" (read: Jewish) lie, and that's what they set out to "prove". This isn't history; this isn't revising history; this is simply denying the truth out of antisemitism.