Starting from build 1591 uniGUI deploys runtime files in portable tar.gz (or tar.xz) format. Though this file is specifically deployed for Linux platform, there is nothing that may keep you from using it for Windows platform as well — simply extract this file into the uniGUI runtime folder. This file contains all JavaScript libraries, built-in themes plus uniGUI custom themes.
Under Linux use the following command to extract the archive: