Python Kalman filtering and optimal estimation library. Implements Kalman filter, particle filter, Extended Kalman filter, Unscented Kalman filter, g-h (alpha-beta), least squares, H Infinity, smoothers, and more. Has companion book 'Kalman and Bayesian Filters in Python'.
One more difference is update()... Ukf takes **hx_args, while Ekf takes hx_args=()
Another difference is UKF's x vector - zeros(dim_x), ekf has this vector transposed.
The EKF does not implement batch_filter or rts. There are probably similar instances of differences between the classes.