Pre Terminal Options
There are a number of ways to run a terminal on the Pre to access its own GNU/Linux command line.
WebOS Internals Terminal
An open source Mojo application with a browser plugin back end. Application:Terminal
None of the ones below are yet full mojo apps.
via Classic - vt100 terminal
The simplest is simply to run a ssh client in Classic. Although TuSSH refuses to connect to localhost/127.0.0.1, pSSH from http://www.sealiesoftware.com/pssh/ works in Motion Classic 126.96.36.199 (note that the version with the improved random number generator at http://www.nekito.net/~dgsachs/palm/pssh-notes.html does not work as of Motion Classic 188.8.131.52).
Another method to get a full screen terminal emulator without exiting the Palm WebOS LunaSysMgr GUI was PalmVNC Terminal.
via Web browser - vt100 terminal: Ajaxterm
Ajaxterm is a python program that uses html & ajax to run a shell that can be accessed over a browser. Unlike the dumb terminal shells below, full screen programs can be run like vi, vim, and nano. Commands like "cd" work as expected.
Tabbing does not work as of version 0.0.2).
via Web browser - dumb terminal
There are some options for running a terminal from the web browser, but they do not support the use of full screen terminal applications (it's like being at a old line-printer terminal, or worse). Since there is this limitation, they are most useful when used in tandem with a text-editor.
via DirectFB - vt100 terminal
There are some options that do support full screen terminal applications, but they run directly under directfb so you have to stop the normal gui while they run: