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.
Parse Direct User Access Terminal mitigates information overload from aviation weather brief downloads. The USA Federal Aviation Administration (FAA) Direct User Access Terminal (DUAT) standard, outlook, and abbreviated weather brief are broken into a hierarchy of files. Each file contains one METAR/NOTAM/PIREP/TAF/etc. Options allow input of HTML source or text, output of HTML or text, and a flat directory or multi-level directory. As separate files, NOTAMS/etc. scripts can quickly identify changed information, or prioritize for relevance. Parsing is lossless and the complete original text can be reconstructed using cpp(1).
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.
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.
Originally based off the program qmail-masq, qmail-masq-user uses qmail and qmail-qfilter to change the From: address of outgoing emails to almost any combination of username, domain, or both. The configuration allows you to specify domain catch-alls, user catch-alls, email catch-alls, specific combinations of users and/or domains, and much more.