a2b invokes conversion tools in sequence to convert files from one type to another, possibly performing some extra processing along the way. Itis a wrapper for many programs like gif2png, latex2html, netpbm, mencoder, ffmpeg, oggenc, etc., that can convert content from one type to another. It can covert text, documents, images, audio, and video and more. Some examples: a2b test.mp3 test.ogg; mencoder_opts="-ss 60 -endpos 10" a2b video.avi clip.flv; a2b -g=subtitles dvd://8 movie.sub; a2b -q http://sam.nipl.net/ sam.aac. That last example downloads the author's Web page, converts it to text with lynx -dump, speaks the text with flite or espeak, and converts the audio file to AAC with faac.
SpamCheetah is a network-level spam filtering solution built around OpenBSD greylisting, tarpit, and blacklisting. It comes with a Web interface and requires zero administration. It does not allow spam to even land in your network, thus saving you precious bandwidth. It does not have the 'false positives' problem of losing legitimate mail.
SpamCheck is an email scanning and quarantine system for Linux systems. Making use of a number of open source technologies, including SpamAssassin, Exim, and MySQL, it provides an easy-to-use, but powerful method to filter email for your domain. Once configured, multiple domains can be added and administered with the Web interface. Email is scanned and scored, non-spam is then passed on to a destination email server, while spam is either blocked or quarantined. Individual users can log in and review their quarantined email, and manage their settings through the Web-based interface.
Synspam uses Netfilter NFQUEUE to catch the source IP address of any machine connecting to your mail server, running multiple tests against it (RBL check, regexp on the reverse name, etc.) before forwarding the connection to the MTA. In order to have as few false positives as possible, a scoring system is used. If the source IP address is believed to be a spammer IP address, the connection can be dropped. There is a dry run mode if you just want to test it, which is the default.
Baruwa (Swahili for letter or mail) is a Web 2.0 MailScanner front-end. It provides an easy to use interface for managing a MailScanner installation. It is used to perform operations such as releasing quarantined messages, spam learning, whitelisting and blacklisting addresses, monitoring the health of the services, etc. Baruwa is implemented using Web 2.0 features (AJAX) where deemed fit. Graphing is also implemented on the client side using SVG, Silverlight, or VML. It includes reporting functionality with an easy to use query builder. Results can be displayed as message lists or graphed as colorful and pretty interactive graphs. Custom MailScanner modules are provided to allow for logging of messages to the MySQL database with SQLite as backup and for managing whitelists and blacklists.
MailChariot's only mission is to get your incoming email (for example from /var/spool/mail), filter it through a spam filter, and put it into a spam or ham mailbox. If you don't agree with the spam filter's decision, you can move it to the notspam or notham mailbox and MailChariot will mark the message as ham or spam respectively. This design is mail client agnostic. It is ideal for use on shared hosts where the provided spam filtering is not effective enough.