This is IboView [v20150424] by Gerald Knizia.
Infomation and updates:
Special thanks go to:
Johannes E. M. N. Klein and Laura Nunes dos Santos Comprido for many useful comments and examples, and for adopting the program already in its infant stage 8)
Peter Knowles and Andreas Köhn for their help and boundless patience with getting it working on MacOS.
References:
G Knizia; Intrinsic atomic orbitals: An unbiased bridge between quantum theory and chemical concepts J. Chem. Theory Comput. 9, 4834 (2013) DOI: 10.1021/ct400687b
(Publications employing IAOs or IBOs should cite this.)
G Knizia and JEMN Klein; Electron flow in reaction mechanisms---revealed from first principles Angew. Chem. Int. Ed. 54, 5518 (2015) DOI: 10.1002/anie.201410637
(Publications employing IboView should cite this, especially if used to trace reaction mechanisms.)
Funding: