The TaxCalc application is now available on Linux for Individual and Standalone practice users. We are currently developing a network version which will be available in the future. As for now, you are able to have a LINUX machine as one of the additional machines if a windows machine acts as the server to hold the database.
If you wish to use the Linux version, follow the instructions in Migrating between different operating systems.
The following Knowledge Base article may also be useful - System requirements for TaxCalc