Is there an Islamic esoteric tradition? Like the Qaballah? I read that the Ismaelits study esoterism, is this true?

1 I read the same, there is an article on the ismailists on totse, but it is only basically criticizing other religions, and giving some history of Islam.

2 There is the Sufee though, who are kind of comparable to chassidic Jews, but moslims.

3 There is Lycossearch.