Bluelog is a Bluetooth site survey tool, designed to tell you how many discoverable devices there are in an area as quickly as possible. Bluelog differs from most Bluetooth scanners in that it prioritizes speed of reporting over anything else (i.e. it doesn't spend time trying to pull detailed data from a device) and doesn't require any user intervention to function. As the name implies, its primary function is to log discovered devices to file rather than to be used interactively. Bluelog could run on a system unattended for long periods of time to collect data. In addition to basic scanning, Bluelog also has a unique feature called "Bluelog Live", which puts results in a constantly updating Web page which you can serve with your HTTP daemon of choice.
skipfish is a high-performance, easy, and sophisticated Web application security testing tool. It features a single-threaded multiplexing HTTP stack, heuristic detection of obscure Web frameworks, and advanced, differential security checks capable of detecting blind injection vulnerabilities, stored XSS, and so forth.
DynaBlast is a fast Apache HTTPD access_log scanner. It can find hosts that exceed a given number of hits in a given time period, printing them to standard output. It has a "fast mode" that can skip lines that have already been parsed. Multiple dynablast instances are avoided by using a lock file. This make it suitable for crontab usage. It can be run by any user, not just root. It can run in parallel, for example, when analyzing different access_log files. It keeps memory consumption down to about 10 kb, by parsing the access_log file one line at a time.
Scandalo is a very efficient and fast mail frontend for the clamdscan virus scanner. In other words, it is a simple mail filter that works as a wrapper for clamd, the famous Clamav antivirus daemon. Once integrated in maildrop or any MTA or MUA, it can quickly read messages and send them to the clamd process for virus scanning using the clamdscan utility. When a virus is found, the message is marked with a header, so you can easily set up your mail filter or MUA to drop, quarantine, or move the infected message to a mail folder.