The tools listed in this appendix are open source for the purposes of remaining as vendor and product agnostic as possible and to highlight excellent tools provided by the open source community. This list is not comprehensive, but consists of some well-known open source projects for their respective uses. In some cases, the open source project has been acquired by a commercial entity. This is not an endorsement of the commercial entity, but of the open source project only. There are several commercial products available for each of these areas and simple Internet searches will provide the available products and vendors. For enterprise implementation, there may be a mix of commercial and open source tools used to accomplish security goals. Tool selection should always consider the total cost of ownership, support, and effectiveness.