In a word: Putty++.
IVT is a VT220 terminal emulator for Windows NT/2000/2003/XP/Vista/Win 7/8/10, that can set up a secure SS, (Kerberized) telnet, connection to a remote host.
It supports multiple (tabbed) sessions of different types in a single window.
IVT can do all things that PuTTY can do, and many more things besides!

If you use a PC to access remote hosts and you care about fast, accurate VT220 terminal emulation with a large tabbed screen, multi-session, color support, fast copy/paste etc. because you use Unix text-mode applications such as EMACS, VI or Midnight Commander, then IVT is a program designed for you.
If you want secure authenticated login, you can use SSH or the Kerberos V5 authentication and encryption support.

If you administer (or use) a large network with many machines, IVT allows you to initialise your working environment with only a few mouse clicks.

Logging in to an array of hosts with either Telnet, Kerberized Telnet, SSH or modem, starting programs there, automatically analyzing the output, customising the keyboard and screen (different key-mappings and colors per host and/or session if you want to) is all easily achieved.

Once you get used to creating sessions with a few clicks and switching between 10, 20 (or even more) parallel sessions without losing track, you'll wonder how you ever got along without it :-)

Designed to work in environments with hundreds of Unix machines, IVT is tailored to make life in such environments easier.