As always, grab the newest version on codeplex.
In addition to the regular upgrades, this version comes with updates to the previously available SlimDX fork.
Don't want to use XNA or SlimDX? No problem! There's now a dependency free version as well! The BEPUphysicsDemos project used to test the dependency-free library still relies on XNA, but the library itself is completely independent.
Here's some jazzy boxswarm-related entertainment, filmed in v1.0.0: