Greetings,
apparently there are messups with the cxxtest.com website.
cxxtest.com has no DNS address RRs (A and AAAA).
Seems to be hosted by Ionos (at least that's the DNS NS/SOA home).
www.cxxtest.com points to cxxtest.github.io (CNAME)
cxxtest.github.io (by way of a 301 return code, permanent redirect) and cxxtest.sourceforge.net (per HTML meta http-equiv="REFRESH" content="0;url=http://cxxtest.com") redirect to the nonexistant cxxtest.com
=> website is "gone".
For people who find this Issue, the website contents seem to reside here:
https://github.com/CxxTest/cxxtest.github.com