Question: What type of license is the open source roguelike video game video released 2012, in which a subset of it's pricing model is a called free-to-play, licensed under?

WURFL (Wireless Universal Resource FiLe) is a set of proprietary application programming interfaces (APIs) and an XML configuration file which contains information about device capabilities and features for a variety of mobile devices, focused on mobile device detection.  Until version 2.2, WURFL was released under an "open source / public domain" license.  Prior to version 2.2, device information was contributed by developers around the world and the WURFL was updated frequently, reflecting new wireless devices coming on the market.  In June 2011, the founder of the WURFL project, Luca Passani, and Steve Kamerman, the author of Tera-WURFL, a popular PHP WURFL API, formed ScientiaMobile, Inc to provide commercial mobile device detection support and services using WURFL.  As of August 30, 2011, the ScientiaMobile WURFL APIs are licensed under a dual-license model, using the AGPL license for non-commercial use and a proprietary commercial license.  The current version of the WURFL database itself is no longer open source. <SEP> <onlyinclude>An open-source license is a type of license for computer software and other products that allows the source code, blueprint or design to be used, modified and/or shared under defined terms and conditions.  This allows end users and commercial companies to review and modify the source code, blueprint or design for their own customization, curiosity or troubleshooting needs.  Open-source licensed software is mostly available free of charge, though this does not necessarily have to be the case.  Licenses which only permit non-commercial redistribution or modification of the source code for personal use only are generally not considered as open-source licenses.  However, open-source licenses may have some restrictions, particularly regarding the expression of respect to the origin of software, such as a requirement to preserve the name of the authors and a copyright statement within the code, or a requirement to redistribute the licensed software only under the same license (as in a copyleft license).  One popular set of open-source software licenses are those approved by the Open Source Initiative (OSI) based on their Open Source Definition (OSD). </onlyinclude> <SEP> Freemium is a pricing strategy by which a product or service (typically a digital offering or application such as software, media, games or web services) is provided free of charge, but money (premium) is charged for additional features, services, or virtual goods.  "Freemium" is a portmanteau of "free" and "premium".  The business model has been in use by software industry since the 1980s as a licensing scheme.  A subset of this model used by the video gaming industry is called free-to-play. <SEP>  "Tales of Maj'Eyal" is available as donation-supported Freeware/Donationware from the developers.  Donations grant some exclusive online features (Freemium model). Tales of Maj'Eyal is an open source roguelike video game released 2012 for Microsoft Windows, Mac OS X, and Linux.  The game may also be purchased through the digital distribution outlets Steam or GOG.  The game's TE4 game engine source code is under a GNU GPLv3 license, the game's assets are licensed for use "with the Tales of Maj'Eyal game only."