Without a Java-capable browser, you will have to log in each time.
Hold the Windows key and press R to get the Run box. Type telnet lord.nuklear.org. You can go full screen by pressing Alt-Enter.
Alternatively, PuTTY is popular.
Hold the Apple key and press Space to open Spotlight. Type terminal to open a terminal. Type telnet lord.nuklear.org
Another popular Telnet app for Mac is iTerm