| Feature | Utilities |
|---|---|
| SSH | Dropbear has both an ssh server and an ssh client that together come in around 100k. It has no external dependencies (I.E. it does not depend on OpenSSL, using a built-in copy of LibTomCrypt instead). It's actively maintained, with a quiet but responsive mailing list. |
| SMTP | ssmtp is an extremely simple MTA. |
| Microperl | microperl is a small standalone perl interpreter that can be built from the perl sources via "make -f Makefile.micro". If you really feel the need for perl on an embedded system, this is where to start. (If you just want a small embedded scripting language to write _new_ code in, Lua seems popular for this purpose. |
In a gui environment, you'll probably want a web browser. Konqueror Embedded requires QT (or QT Embedded), but not KDE. The Dillo requires GTK+, but not Gnome. Or you can try the graphical version of links.
For more information, you probably want to look at buildroot and TinyGentoo, which build and use tiny utilities for all sorts of things.