Comparing the situation with GNU coreutils, which has a long name of 'GNU core utilities', I suggest we use 'GNU Inetutils', 'Inetutils', or 'inetutils' as appropriate, with a long name of 'GNU network utilities'.
As a side note, GNU coreutils uses a lower case letter. Whilst as Sergey pointed out, GNU Mailutils uses a capital letter. Sergey, you OK with using a capital letter as appropriate? This would result in two minor actions: 1) Changing InetUtils to Inetutils in libtelnet/. 2) Changing 'GNU internet utilities' to 'GNU network utilities' on the web page. Sounds like a plan!
