"Lisp mode.  Sets the 'lisp' and 'showmatch' options on."

which is not very helpful, but the link to 

http://www.vim.org/html/options.html#'lisp'

has more information.

> Is there also an 
> interpreter, or do I need to get one?

IIRC, you are using Slackware 7.1.  I think there was a Lisp interpreter
included with it.  There is one in Slack 8.0.
 
Glenn McDavid
mailto:gmcdavid at winternet.com
http://www.winternet.com/~gmcdavid