BoofCV is described as 'open source library written from scratch for real-time computer vision. Its functionality includes, low-level image processing, camera calibration, feature detection/tracking, structure-from-motion, fiducial detection, and recognition'. There are three alternatives to BoofCV for Linux, Mac, Windows and Android. The best alternative is OpenCV, which is both free and Open Source. Other great apps like BoofCV are SimpleCV (Free, Open Source) and FastCV Computer Vision (Free).
SimpleCV is a Python interface to several powerful open source computer vision libraries in a single convenient package. With it, your software can have access to high level algorithms in feature detection, filtering, and pattern recognition in a unified framework.