aircrack-ng is a set of tools for auditing wireless networks. It's an enhanced/reborn version of aircrack. It consists of airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), airdecap (decrypts WEP/WPA capture files), and some tools to handle capture files (merge, convert, etc.).
KJam is a very fast build tool. It is a make replacement, and uses a syntax similar to Jam, but is much more powerful than the original. It has built-in dependency scanning, per-target viewpathing, C-like control flow, and a built-in sh-like shell. It is optimized for multi-processor machines. It can accelerate software builds by launching build actions on a distributed peer to peer network of build servers. It is designed to support large projects with thousands of targets, or projects requiring building on many target architectures.
BDDs [bry86] (or more precisely ROBDDs) are efficient data structures for representing a boolean formula. They are widely used in formal verification, in particular symbolic model-checking. Ruby- BDD, based on Buddy, provides access to BDDs from Ruby, a powerful and very easy to use object-oriented language. The purposes are quick prototyping and education.
ike-scan discovers IPsec VPN servers, and can fingerprint them using UDP backoff and Vendor ID fingerprinting techniques. It supports IKE Main Mode and Aggressive Mode. ike-scan allows flexible specification of the outgoing IKE packet, and decodes the response packets. It also supports pre-shared key cracking for IKE aggressive mode with pre-shared key authentication.
The d command runs a command in the background and redirects its output to a file. The output file is annotated with start and end time, the actual command used, cwd, host, etc. You can ask the d command to extract the last command from the output file and run it again, you can ask it to append to the file or not, and other goodies. It comes with handy little programs to look at the output, tail it, etc. It is sort of trivial, but has been streamlined over many years.