+ - Open authentication system. Can we use PAM? Is SASL an adequate
+ mapping of PAM to the network, or useful in some other way?
+
+ - Resume interrupted transfers without the --partial flag. We need
+ to leave the temporary file behind, and then know to use it. This
+ leaves a risk of large temporary files accumulating, which is not
+ good. Perhaps it should be off by default.
+
+ - tcpwrappers support. Should be trivial; can already be done
+ through tcpd or inetd.
+
+ - Socks support built in. It's not clear this is any better than
+ just linking against the socks library, though.
+
+ - When run over SSH, invoke with predictable command-line arguments,
+ so that people can restrict what commands sshd will run. (Is this
+ really required?)
+
+ - Comparison mode: give a list of which files are new, gone, or
+ different. Set return code depending on whether anything has
+ changed.
+
+ - Internationalized messages (gettext?)
+
+ - Optionally use real regexps rather than globs?
+
+ - Show overall progress. Pretty hard to do, especially if we insist
+ on not scanning the directory tree up front.
+
+
+Regression testing:
+
+ - Support automatic testing.
+
+ - Have hard internal timeouts against hangs.
+
+ - Be deterministic.
+
+ - Measure performance.
+