The license looks to be Creative Commons non-commercial, which means it isn’t open source, only source-available.
To be clear: the license chosen prohibits anyone who forks floorp and includes these extra bits from trying to make money from it, but the developer still intends on publishing the source code so it can still be scrutinized.
The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.