Use \url{} to mark URLs.
diff --git a/Doc/ext.tex b/Doc/ext.tex
index 596dd92..22f7ebc 100644
--- a/Doc/ext.tex
+++ b/Doc/ext.tex
@@ -1239,7 +1239,7 @@
Before you build Python, you first need to fetch and build the \code{dl}
package written by Jack Jansen. This is available by anonymous ftp
-from host \file{ftp.cwi.nl}, directory \file{pub/dynload}, file
+from \url{ftp://ftp.cwi.nl/pub/dynload}, file
\file{dl-1.6.tar.Z}. (The version number may change.) Follow the
instructions in the package's \file{README} file to build it.
@@ -1261,10 +1261,10 @@
You need to fetch and build two packages.
One is GNU DLD. All development of this code has been done with DLD
-version 3.2.3, which is available by anonymous ftp from host
-\file{ftp.cwi.nl}, directory \file{pub/dynload}, file
+version 3.2.3, which is available by anonymous ftp from
+\url{ftp://ftp.cwi.nl/pub/dynload}, file
\file{dld-3.2.3.tar.Z}. (A more recent version of DLD is available
-via \file{http://www-swiss.ai.mit.edu/~jaffer/DLD.html} but this has
+via \url{http://www-swiss.ai.mit.edu/~jaffer/DLD.html} but this has
not been tested.)
The other package needed is an
emulation of Jack Jansen's \code{dl} package that I wrote on top of