Email sends email to remote SMTP servers via the command line, which makes it useful in cron jobs. It will send to any RFC standard remote ESMTP server, is TLS/SSL enabled, and will allow you to encrypt, sign, and design your message on the fly. It has the capability to use signature files with dynamic options, address book functionality, and users can also attach pictures, binary files, documents, or whatever they want. It is completely compatible with GNUPG for encryption and signing, and is easy to configure and use.
elfsign provides tools and an interface for signing and verifying ELF binary images with certificates. The functionality is similar to Microsoft's Authenticode technology in that binaries can be tagged with an owner as well as proof that they have not been modified or tampered with.
Webtunnel is a network utility that encapsulates arbitrary data in HTTP and transmits it through a Web server. In that regard, it is similar to httptunnel. However, its server component runs in the context of a Web server as a CGI application (with optional FastCGI support), so it does not need its own port. It supports most things that the Web server supports, such as authentication, HTTP 1.1, HTTPS, and client certificates. It uses simple requests and responses so it works seamlessly through forward and reverse proxies.
Procwatch is security monitor written in Perl that watches a /proc filesystem for new processes. When a process is created, procwatch reports the time, the username, the PID, and the binary that was run. Its output is suitable for logging to log files and is geared for system administrators who are testing a new but as yet untrusted UNIX system. Although it cannot detect, and is not proof against, hacked loadable kernel modules that have modified /proc, it is useful in watching for possible rogue binaries.