BaySAC (and RANSAC and PROSAC and SimSAC) for Essential Matrix estimation and Homography estimation. Topdown and non-linear refinement of solution.
Several different 5-point Essential Matrix estimation algorithms.
See workspace/cameraGeom/geom/EssentialMatGoldStandard.cpp for Levenberg-Marquardt refinement of E (also function to minimise Sampson error by LM which is a lot faster and works just as well).
Homography decomposition (fit rotation/translation/plane-normal by Levenberg refinement) -- see geom.cpp
Bag-of-Words library: Real-time performance and dynamic retraining. Supports 10k+ images. Fast pairwise correspondences.