Some time ago when I was doing my first DJ gig at WNHU, my college's radio station, I was sifting through the station's massive library and came across a band called Don Caballero and it blew my mind. Since then I've been fascinated by math rock and all it's variations. Numerous forums and blogs just like this one helped fuel that fascination and built a pretty substantial library of music for myself. Didn't want to post any repeats (you guys have covered a lot of ground over the years!) but was surprised these guys haven't been mentioned on swords.
Planets are a drum and bass duo from Napa, CA who I once heard described as "maze-rock" because they were "too crazy for math rock". Tag squabbling aside this is hyperactive music that takes more than a few listens to digest but the impressive level of technique is apparent right away. Paul Slack, previously of SWIMS, sounds like he's playing two basses at once through impressive use of octave pedals but I saw them live and they pull it off and then some (not to mention they wear white cotton body suits and play crazy video clips through a projector pointed at themselves.) Certainly not for everyone but mind blowing in its composition and execution, I hear something new each listen.
Their bandcamp has their latest ep, Turbo Jamz and a few off singles for free which I've grouped together below but I recommend starting with their s/t debut. Haven't heard much from them lately but enough writing, go listen.
Planets - 2009
Turbo Jamz!!! EP - 2010