The ASTRA Toolbox is a MATLAB and Python toolbox of high-performance GPU primitives for 2D and 3D tomography. The supported geometries are 2D parallel, fan beam, as well as 3D parallel and cone beam, all with highly flexible source/detector positioning. A large number of 2D and 3D algorithms are available, including FBP, SIRT, SART, CGLS. The basic forward and backward projection operations are GPU-accelerated, and directly callable from MATLAB and Python to enable building new algorithms.
Source Code: Download Page, GitHub
Tutorials: Documentation, ASTRA-Doc (GitHub), Installation, Training School, News and Releases
References: Paper 1, Paper 2 & Paper 3 (parallel beam GPU implementation)
NMMItools 