Below are descriptor calculators available for download. They were mostly written by dr Steven Enoch while he worked at Cyprotex. It is thanks to Prof. David E Leahy now available to the community as opensource. We have taken the responsibility of maintaining the code.

E-states and HE-states (Download)
Based on work by Kier and Hall.
Dependencies: OpenBabel

LSER (Download)
Linear Solvation Energy Relationship descriptors are based on work by Abraham.
Dependencies: OpenBabel

hQSAR (Download)
hQSAR descriptors
Dependencies: OpenBabel, PerlMol

Below are wrappers for MOPAC and RECON executables. The executables are not included. Please contact the authors for licences and executables.
MOPAC (Download)
Calculates quantum mechanical descriptors from MOPAC2009.
Dependencies: MOPAC2009, MarvinBeans

RECON (Download)
Calculates TAE descriptors using the RECON program.
Dependencies: RECON