Version 2.5 of CTSim has been released! New Features of CTSim version 2.5: - Now compiles with Microsoft Visual C++. - First Microsoft Windows graphical user interface - Bug fixes and modest documentation and program improvements over version 2.0 New Features of CTSim version 2.0: - Entire code-base cleaned up, re-written, and converted from C to C++. - Graphical user interface now included! Animation of projection and reconstruction processes. Displays projection and image files. Uses platform-independent wxWindows library so can run on UNIX and Microsoft Windows platforms. - Integrated G2 library for graphical display from command line tools (UNIX only) - Added frequency-based filtering. Can provide significant speed-up in reconstructions compared to convolution-based filtering. - Added highly-optimized backprojection method (idiff3) - New command-line tools added for image statistics and comparisons with both text and graphical outputs.