The Linux Virtual Server Project is a project to cluster many real servers together into a highly available, high-performance virtual server. The LVS load balancer handles connections from clients and passes them on the the real servers (so-called Layer 4 switching) and can virtualize almost any TCP or UDP service, like HTTP, HTTPS, NNTP, FTP, DNS, ssh, POP3, IMAP4, SMTP, etc. It is fully transparent to the client accessing the virtual service.
Ganymede is a metadirectory system, primarily intended for UNIX-like environments, but capable of being run with some effort on any server supporting Java 1.1.7 or better. Ganymede supports NIS, DNS, and other network information services, and allows many administrators to work together simultaneously to administer defined subsets of your network directory data. Any system capable of running Java applets with Swing can run the Ganymede client.
Pidentd v3 is a much improved version of the original Ident daemon both in terms of speed, code quality and features. Features include multithreading, a "configure" script, startup autodetection, much clearer/rewritten C code, doesn't run as root after startup, has a configuration file and can be started from /etc/inittab (on systems using a SysV init).
fsh is a tool for establishing an ssh tunnel for remote execution of commands without requiring an ssh authentication on every connection. Once the tunnel is established, remote commands can be executed almost instantaneously. This makes systems such as remote cvs over ssh much faster. It includes fcp, an rcp variant that uses fsh.
Pocket Linux is an almost minimal, one floppy linux system designed to quickly convert PC workstation into secure linux-based workstation using ssh to connect to remote host (other networking clients are also supported). It supports bootp for determining host IP and other network parameters (there's also manual configuration possible, but bootp is recommended). In addition to workstations equipped with a network card (ethernet or arcnet), you can also use Pocket Linux on a PC equipped with a modem. Modem is automatically detected and then PPP connection is made.