Tournament Director for Windows uses the ECF Swiss chess pairing system.

There are numerous different Swiss chess pairing methods. The main ones are:

• FIDE Swiss pairing rules
  
  
• ECF Swiss pairing systems
  

The FIDE Swiss Pairing rules above are more up to date than those on the FIDE web site. These were provided to by the chairman of the FIDE Pairings committee. The rules on the FIDE web site do not include the latest revision.

Other pairings systems

• Wikipedia provides more details on Swiss pairings sytems and its variants
  
  

• Dubov system (also recognised by FIDE) 
   
• Kaps pairing system (not sure of the origins of this system)