Hacked up this afternoon, not quite ready for commital but would appreciate feedback: slime on a local (a.k.a unix domain) socket using half of the attachtty/detachtty utility as a socket shim.
Why? Two reasons:
(1) access control can be done by setting appropriate filesystem permissions on the directory containing the socket (or in Linux but not portably, on the socket itself) - so, a safe way to run slime on shared hosts that doesn't involve cooking up an authentication protocol
(2) attachtty can connect across a network using ssh, so you can control a remote lisp this way as well.
How to use it:
Server-site, create-swank-server has a new keyword argument :af, which defaults to :inet, and can also be :local
* (swank:create-inet-server "/home/dan/.swank/socket" :af :local)
Client-side, slime-connect is renamed to slime-connect/inet, and there's a new function (slime-connect/local pathname)
M-x slime-connect /home/dan/.swank/socket RET
or from another machine
M-x slime-connect me@lisp.example.com:/home/dan/.swank/socket RET
Opinions? You can get attachtty as part of detachtty, in Debian, FreeBSD ports, or from http://www.cliki.net/detachtty
-dan