The BIANCHI code provides functionality to support the simulation of Bianchi Type $\text{VII}_h$ induced temperature fluctuations in CMB maps of a universe with shear and rotation.
The implementation is based on the solutions to the Bianchi models derived by Barrow et al. (1985), which do not incorporate any dark energy component. Functionality is provided to compute the induced fluctuations on the sphere directly in either real or harmonic space. For a description of the equations implemented to perform the Bianchi simulations see the Appendix of our paper: Non-Gaussianity detections in the Bianchi $\text{VII}_h$ corrected WMAP 1-year data made with directional spherical wavelets.
Functionality to support functions defined on the sphere is provided by the S2 code.