Visprint makes cool fractal fingerprint PNG images based on the contents of any file. The image will be different for almost every file with even slightly different contents. Visprint uses the IFS fractal generation process pioneered by Michael Barnsley. It is a way to create images that are self-similar to infinite depths. In other words, the picture is made up of smaller versions of itself. Visprint takes a hash function checksum as its input.
vlock is a program to lock one or more sessions on the Linux console. This is especially useful for Linux machines which have multiple users with access to the console. One user may lock his or her session(s) while still allowing other users to use the system on other virtual consoles. If desired, the entire console may be locked and virtual console switching disabled.
The vomit utility converts a Cisco IP phone conversation into a wav file that can be played with ordinary sound players. The phone conversation can either be played directly from the network or from a tcpdump output file. Vomit is also capable of inserting wavfiles into ongoing telephone conversations. It can be used as a network debugging tool, a speaker phone, etc.
vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm with a key length of up to 576 bits (may be downgraded to a minimum of 0 bits to suit any legal restrictions).
vthrottle is an implementation of an SMTP throttling engine for Sendmail servers, based upon M. Williamson's mechanisms, as described in his 2003 Usenix Security paper. It allows the administrator to control how much email users and hosts may send, hindering the rapid spread of viruses, worms, and spam. Exceptions can be made using a whitelist mechanism, which can be generated manually or with the included tool "vmeasure". vthrottle tells the misbehaving client to hold on to the deferred mail and resend it at a later time.
w3af (Web Application Attack and Audit Framework) is a framework for finding and exploiting Web application vulnerabilities. It is easy to use and extend. The project has more than 125 plugins which check for SQL injection, cross site scripting (XSS), remote file inclusion, and more.