Brutus is distributed under a dual license model. This means that users can choose to use Brutus under the terms of the GPL or under a commercial license.
Products that are distributed under the term of the GPL is generally available free of charge (maybe except for a distribution fee) and the GPL ensures that you have the legal rights to modify, use and distribute said product. It is so with OMCs products too. You can download Brutus free of charge under the GPL and all we ask is that you abide by the terms of the GPL.
OMC offers a commercial license for organizations that do not want to distribute their products under the terms of the GPL. Commercial customers will get a commercially supported product and will retain full control over the distribution conditions of their Brutus-enabled products.