antiX User Manager is released under the Apache Software License 2.0, whose full text is both online and onboard at: at: /usr/share/common-licenses/Apache-2.0. The core statement is as follows:
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Portions of the code came originally from the muser application of SimplyMEPIS, which was similarly covered by the Apache 2.0 license. Those portions concern utility functions and some logic regarding gui interaction; they have been thoroughly reworked here with permission from the developer Warren Woodford.