There aren't many of us that need to cut frame timbers, railroad ties and things beyond the scope of your average circular or table saw. But for those that do, and need to do it on-site, Festool makes the SSU 200 Sword Saw.
As with the Prazi Beam Cutter, the Sword Saw is a combination of a circular saw and a chainsaw; but whereas Prazi's invention is a DIY job, Festool's is plug-and-play and meant to ride along one of their tracks, providing straight-line accuracy:
What they need to invent next: A microphone windscreen.While the video above shows the cut being made without a dust collector, you can still see the port. To see it with the dust collection in action, check out the older video below from Festool's former sister company Protool. Here we see their apparently identical UniverS Sword Saw chewing through huge sheets of insulation, with very little debris flying around in the air, so the DC seems to be pretty good:
Protool and Festool, by the way, have since been conflated by their parent company, keeping the latter's name.