I use bit fields a lot and happened to notice that modular-bitfield has recent updates and cleanup, thanks to Colin Snover.
This is exciting to me because modular-bitfield has what I consider an ideal API. Because it wasn't maintained I've been using the bitfield crate instead. bitfield works very well, but its doc is somewhat lacking and I don't think its API is nearly as nice as modular-bitfield.
EDIT: Colin Snover mentioned his involvement here.