and video games, is challenged by "licensed, not sold" EULAs of digital distributors like Steam. In the European Union, the European Court of Justice held that a copyright holder cannot oppose the resale of a digitally sold software, in accordance with the rule of copyright exhaustion on first sale as ownership is transferred, and questions therefore the "licensed, not sold" EULA. The Swiss-based company UsedSoft innovated the resale of business software and fought for this right in court. In Europe, EU Directive 2009/24/EC expressly permits trading used computer programs. Proprietary software licenses The hallmark of proprietary software licenses is that the software publisher grants the use of one or more copies of software under the end-user license agreement (EULA), but ownership of those copies remains with the software publisher (hence use of the term "proprietary"). This feature of proprietary software licenses means that certain rights regarding the software are reserved by the software publisher. Therefore, it is typical of EULAs to include terms which define the uses of the software, such as the number of installations allowed or the terms of distribution. The most significant effect of this form of licensing is that, if ownership of the software remains with the software publisher, then the end-user must accept the software license. In other words, without acceptance of the license, the end-user may not use the software at all. One example of such a proprietary software license is the license for Microsoft Windows. As is usually the case with proprietary software licenses, this license contains an extensive list of activities which are restricted, such as: reverse engineering, simultaneous use of the software by multiple users, and publication of benchmarks or performance tests. There are numerous types of licensing models, varying from simple perpetual licenses and floating licenses (also known as concurrent licenses) to more advanced models such as the metered license. The most common licensing models are per single user (named user, client, node) or per user in the appropriate volume discount level, while some manufacturers accumulate existing licenses. These open volume license programs are typically called open license program (OLP), transactional license program (TLP), volume license program (VLP) etc. and are contrary to the contractual license program (CLP), where the customer commits to purchase a certain number of licenses over a fixed period (mostly two years). Licensing per concurrent/floating user also occurs, where all users in a network have access