Since I don't know anything about IDM other than that it's basically tongue-in-cheek pretentiousness done correctly, I'm going to talk about breakcore, which I don't really know anything about either. But I listen to breakcore, so that should mean something. I mean, my "Jungle 101" still consists of basically "junglists are angry people who stab each other."

Anyway, breakcore, since Randolyn asked:

Breakcore is like hardcore IDM, or like jungle on crack, or like fifteen people trying to play a single set of drums, or even soft jazz. It often tries to be mocking or unpleasant, tearing apart other styles of music by mimicking their styles and then running everything through a heavy glitch or distortion.
Breakcore is anti-dance music in the sense of rejecting ideas about patterns, repetition and the limits of confining oneself to genres. Breakcore is not so much a unified style as a rejection of everything, including itself. A lot of it is loud and hard and fast, as a lot of the artists ported over from hardcore, both electronic and rock. But there is also extensions into free jazz, dub, and ambient.

Artists include:
Venetian Snares
Doormouse
Dev-Null
Bong-Ra
Hecate
Baseck
Duran Duran Duran
KnifeHandChop
Xanopticon
Electric Kettle