If you have Toad software installed on your workstation, you should be able to connect remotely to an Oracle database on just about any platform or operating system regardless of whether it resides on Unix or Windows. This, of course, assumes you have the appropriate privileges to log into the database.
Toad, however, does require SQL*Net (or Oracle Net) to be able to connect, so you should install Oracle Client on your workstation. You will also need a current tnsnames.ora file on your workstation. This file should contain entries for all databases you wish to connect to, which will help Toad (and other applications) establish a connection.
This was first published in May 2006