Buildkernel is an intelligent shell script that automates the task of building a Linux kernel. For beginning users, it handles the process from beginning to end, prompting the user when they have to do something. Advanced users can use it to build multiple kernels with little effort. Buildkernel will download kernel and pcmcia source, remove unnecessary code, create symlinks, automatically patch the kernel, build the kernel, modules, and pcmcia modules (nicely), and install them to hard disk or floppy, running LILO as necessary.
Mason is a tool that interactively builds a firewall using Linux' ipfwadm or ipchains firewalling. You leave mason running on the firewall machine while you are making all the kinds of connections that you want the firewall to support (and want it to block). Mason gives you a list of firewall rules that exactly allow and block those connections. It can either build a firewall from scratch for you or supplement an existing firewall.
rsync-backup automates the process of backing up multiple systems to one or more backup servers. It focuses on making the process secure. It encrypts the backup going across the wire, only ships changed data, runs the server as root to preserve permissions and ownership, keeps people from seeing each other's backups, and doesn't require the server to trust any files sent from the clients. It doesn't ship password files, key files, nor other sensitive files across the wire, but backs them up locally instead. Admins may use one key for everyone (backups named after the client IP) or allow named backups (when a machine may change IP or when multiple independant backups may need to be made from one machine).
ssh-keyinstall is a script that helps an ssh user set up the keys at both ends of an ssh connection. It creates an rsa or dsa key if needed and copies the public half to the server. Once the process is done, you'll be able to log in with the passphrase and key instead of a password.
sa-blacklist is a hand-checked list of over 10,000 spammer domains. It's formatted for Exim, Postfix, Privoxy, Qmail, Spamassassin, Squid, and Sendmail. Depending on the application, it can block or score either on the sender domain and/or the embedded URLs in the spam. It's also available as an RBL (a DNS-based lookup of spammer domains).
> scp ~/.ssh/identity.pub
> Hmm, worth it.
For ssh1, that's just about it. What about ssh2? The soup of filenames and key conversions gets a lot uglier with the different flavors of ssh2.