Mask R-CNN
Software / App
An earlier open-source model from Meta that Roboflow has been a believer in, cited as a precursor to SAM.
Mentioned in 2 videos
Videos Mentioning Mask R-CNN

SAM 3: The Eyes for AI — Nikhila & Pengchuan (Meta Superintelligence), ft. Joseph Nelson (Roboflow)
Latent Space
An earlier open-source model from Meta that Roboflow has been a believer in, cited as a precursor to SAM.

MIT 6.S094: Deep Learning for Human Sensing
Lex Fridman
An extension of R-CNN that adds instance segmentation, mentioned as a state-of-the-art localization network.