read_file(name) := block([file, s, L], file: openr(name), L: [],
while stringp(s: readline(file)) do L: cons(s, L), close(file), L)$

u: read_file("C:/my/mxm/unixdict.txt")$

v: map(lambda([s], [ssort(s), s]), u)$

w: sort(v, lambda([x, y], orderlessp(x[1], y[1])))$

ana(L) := block([m, n, p, r, u, v, w],
L: endcons(["", ""], L),
n: length(L),
r: "",
m: 0,
v: [ ],
w: [ ],
for i from 1 thru n do (
   u: L[i],
   if r = u[1] then (
      w: cons(u[2], w)
   ) else (
      p: length(w),
      if p >= m then (
         if p > m then (m: p, v: []),
         v: cons(w, v)
      ),
      w: [u[2]],
      r: u[1]
   )
),
v)$

ana(w);
/* [["evil", "levi", "live", "veil", "vile"],
    ["elan", "lane", "lean", "lena", "neal"],
    ["alger", "glare", "lager", "large", "regal"],
    ["angel", "angle", "galen", "glean", "lange"],
    ["caret", "carte", "cater", "crate", "trace"],
    ["abel", "able", "bale", "bela", "elba"]] */