This is an NDT server.
You can run an NDT7 test (recommended) by going to ndt7.html
You can run an NDT5 test (legacy, less recommended) by going to embed.html or by connecting to the configured ports (the defaults are 3001 and 3010).
NDT7 is recommended for all new clients. NDT5 is for existing clients
(including all versions before 5) that have not yet been ported to NDT7. The
version "NDT6" was skipped entirely as IPv6 has been supported by NDT for
many years, and the name NDT6 risked confusion with the naming scheme used by
ping6 and the like.
This server is open source, and the code for it may be found at github.com/m-lab/ndt-server