Published by B Jain, New Delhi to a good standard.  

PLEASE NOTE THAT THERE IS NO CD WITH CURRENT VERSIONS AS 9.1 SOFTWARE ENDED WITH WINDOWS XP.

This is the largest edition with the most entries. The more recent Essential Synthesis has concentrated on the more established information.
Main features are as follows:
Remedies of subrubrics copied to main rubric where appropriate. eg Calc is now in main Jealousy rubric, which was previously only in 3 subrubrics. All remedies from the six Boger-Boenninghausen Repertories added in their entirety.
More remedy occurrences 926,200 (Synthesis 8 had 750,000)
1,491,243 author references (Synthesis 8 had 1million)
More cross references: 16,578 (Synthesis 8 had 14,000).
Over 10,000 referring rubrics (Synthesis 8 had 8,000).
Over 700 new corrections to Kent' Repertory.( Synthesis 8 had 300 )
Over 16,000 cross references ( Synthesis 8 had 14,000)
Over 10,000 synonyms (Synthesis 8 had 8,000)
655 contributors, worldwide team of 150 people - the result of 18 years work. The 9.1 edition includes many of the more modern provings.