It is a masterpiece of tech, eminently useful.
A testament to quality development work.
An example of what can be achieved and how much our community benefits from good software.
The Redbean 2.0 license is intriguing (snip):
" Copyright 2020 Justine Alexandra Roberts Tunney │ │ │ │ Permission to use, copy, modify, and/or distribute this software for │ │ any purpose with or without fee is hereby granted, provided that the │ │ above copyright notice and this permission notice appear in all copies. │ "
Seems to assert the (FSF) four freedoms well, all is good in the world, it can be used and contributed to safely by all.