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 and TorsionChecker can be obtained from BioSolveIT free of charge for academic use from here.
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.