A recent publication "Optimization and Evaluation of Site-Identification by Ligand Competitive Saturation (SILCS) as a Tool for Target-Based Ligand Optimization" DOI caught my eye. Predicting ligand binding affinities is a very challenging process and whilst free energy perturbation methods have proved useful they are very computationally demanding. SILCS looks to give similar accuracy but with reduced computational demands.
The software is available from SILCSBIO and whilst it requires significant compute resources or access to a virtual cluster using Amazon Web Services, the SilcsBio Graphical User Interface (GUI) enables running SILCS and SSFEP simulations and analysing results through a GUI instead of the command line and is available for Mac OSX and Windows. Visualisation of results uses VMD or PYMOL plugins.