The TorsionAnalyzer is a graphical user interface authored by Christin Schärfer enabling the visual inspection of torsion angles in molecules . The software displays a molecule in a conformation of interest and highlights bonds which exhibit geometrically unusual torsion angles. The software is a result of a collaboration project between Roche, Basel and the ZBH. It is centered around an expert collection of torsion rules[1,2] derived from high quality crystallographic data from the Cambridge Structural Database.
With the TorsionAnalyzer, you can e.g.
- visually inspect the torsion angles of a given molecule and compare the angles to the CSD
- add or modify torsion rules, defined as SMARTS
- recalculate angle frequencies based on your own data set
- calculate conformations based on the given torsion library 
- calculate the Torsion Fingerprint TFD of a molecule 
TorsionChecker is a command-line tool to evaluate large quantities of molecules with a given torsion library. Each torsion bond with its matching torsion rule, angle, observed frequency in the CSD, and quality category are listed in a result table.
The TorsionAnalyzer is freely available for academic users for Linux (64 and 32bit) as well as Mac and Windows as part of our NAOMI ChemBio Suite. Non-academic users can get an evaluation license free of charge. Only minimal setup steps are required to run the TorsionAnalyzer. All feedback is highly appreciated.
People and references
 Schärfer, C., Schulz-Gasch, T., Ehrlich, H.C., Guba, W., Rarey, M., Stahl, M. (2013). Torsion Angle Preferences in Drug-like Chemical Space: A Comprehensive Guide. Journal of Medicinal Chemistry, 56 (6):2016-28.
 Guba, W.; Meyder, A.; Rarey, M.; Hert, J. (2015). Torsion Library Reloaded: A New Version of Expert-Derived SMARTS rules for Assessing Conformations of Small Molecules. Journal of Chemical Information and Modeling:accepted.
 Schärfer, C.; Schulz-Gasch, T.; Hert, J.; Heinzerling, L. ; Schulz, B.; Inhester, T.; Stahl, M.; Rarey, M. (2013). CONFECT: Conformations from an Expert Collection of Torsion Patterns.ChemMedChem, 8:1690-1700.
 Schulz-Gasch, T., Schärfer, C., Guba, W., Rarey, M. (2012). TFD: Torsion Fingerprints As a New Measure To Compare Small Molecule Conformations. Journal of Chemical Information and Modeling, 52(6):1499-1512.