Octobat - Octobat provides automated tax-compliance and accounting for digital businesses.
TaxBrain - TaxBrain is a taxation filing software that enables users to calculate their taxes easily, and they can file them without any trouble.
Avalara - Cut tax compliance costs, not corners. Avalara automates tax compliance and can help improve accuracy while reducing costs.
eSmart Tax - eSmart Tax is an easy-to-use, eFile tax preparation and filing service. There's no software to download and the process is straight-forward and secure.
Taxamo - SaaS solution for the new 2015 EU VAT rules
TaxSlayer.com - Tax preparation software and proud sponsor of Dale Earnhardt, Jr.