Sybiz Software 
PC accounting software handling the Goods and Service Tax (GST), and Business Activity Statement (BAS).
http://www.sybiz.com.au/Eurofield Information Solutions 
Providers of an Australian Income Tax Law research kit.
http://www.eis.com.au/law/IncTaxLawKit.html
PAYGEasy 
Australian cashbook style software package for the PC, enables easy production of BAS, GST and PAYG processing.
http://www.payge.com.au/
MYOB Products 
Software for accountants and practices.
http://accountant.myob.com.au/products/
KPMG Tax Management Technology 
Offers corporate income tax and fringe benefits tax software.
http://www.kpmg.com.au/default.aspx?tabid=207