GNU parallel is a shell tool for executing jobs in parallel locally or using remote computers. A job is typically a single command or a small script that has to be run for each of the lines in the input. The typical input is a list of files, a list of hosts, a list of users, a list of URLs, or a list of tables. If you use xargs today you will find GNU parallel very easy to use, as GNU parallel is written to have the same options as xargs. If you write loops in shell, you will find GNU parallel may be able to replace most of the loops and make them run faster by running several jobs in parallel. GNU parallel makes sure output from the commands is the same output as you would get had you run the commands sequentially. This makes it possible to use output from GNU parallel as input for other programs.
DataReel is a free, cross-platform database and communications toolkit. It can be used to rapidly develop and deploy multi-threaded database and communications applications. The DataReel toolkit is composed of a modular C++ library designed to build cross-platform infrastructures for end-user applications, embedded systems, and reusable libraries. DataReel's unique modular design simplifies adaptation, allowing you to determine the level of complexity. DataReel makes Internet connectivity and database programming easy.
RFC 2015 defines a proposed Internet standard for sending PGP-encrypted email. This PGP/MIME has been incorporated into several MUAs such as Mutt and (with the AEGYPTEN project) KMail. However, a lot of email clients still don't support it. pgp-mime-handler can decrypt/verify such messages via a pipe, so it can be used as an email filter in many programs or scripts.
Spam Rule is a shell script that is designed to act as a filter for incoming mail on a qmail system. It runs between qmail-smtpd and qmail-queue, and can be used for any kind of filtering, although it was originally designed to block mail based on DNS blacklists (i.e. "RBLs"). Spam Rule is based upon the need to use different filtering rules based on who is receiving the message.
mailagent uses lex-like rules to match messages and run rich set of commands. Mail can be stored in mailboxes, forwarded, piped through external applications, posted to newsgroups, checked for duplicates, annotated, or deleted. Headers can be pruned and digests burst. Additional commands can be written in Perl.