OpenFOAM is an open source toolkit for CFD simulation. Distributed under the GPL licensing, you will have access to the full toolkit and you will have the ability to extend the toolkit with your own custom solvers.
OpenFOAM runs on multiple Linux platforms. You can run simulations on Windows in a virtual machine, and you can also run OpenFOAM in the cloud using Amazon's EC2 cloud services.
Support, training, and services are broadly available to help you and your company make the most of OpenFOAM.