GNU grep is based on a fast lazy-state deterministic matcher (about twice as fast as stock Unix egrep) hybridized with a Boyer-Moore-Gosper search for a fixed string that eliminates impossible text from being considered by the full regexp matcher without necessarily having to look at every character. The result is typically many times faster than Unix grep or egrep.
HTTrack is an easy-to-use offline browser utility. It allows you to download a Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the mirrored Web site in your browser, and you can browse the site from link to link, as if you were viewing it online. HTTrack can also update an existing mirrored site, and resume interrupted downloads. WebHTTrack is a Web-based GUI for HTTrack.
xjobs runs several jobs in parallel and limits the number of jobs running at once so that every processor of the machine is busy, but not overloaded. A batch of long-running processes invoked from the shell are normally executed one after another, no matter how many processors are available. xjobs allows batching those jobs while still keeping the machine busy. The interface of xjobs is similar to that of xargs.
Elm Millennium Edition is a text-based mail client. There are two branches: Elm 2.4ME+, which is based on Elm 2.4, and Elm ME+ 2.5, which also incorporates some code from Elm 2.5. Elm Millennium Edition contains enhanced MIME and character set support. A subset of UTF-8 (Unicode) is handled. It can read mail from a local mbox and POP and IMAP folders and can pass mail to the PGP or GPG programs. It can also view digests as a mailbox and reassemble fragmented (message/partial) messages. It includes modules for TLS/SSL, iconv, and SMTP.
Web Calendar is a powerful group calendaring and scheduling system. It is a Web based application that makes it easy to publish and manage calendar events on the internet. It includes an impressive set of features, including an easy to use interface, rich functionality, and sophisticated scheduling. It is a CGI application. It runs under your Web server, so to use it, all you need is a browser. There is no proprietary software that needs to be installed on the client side. Web Calendar runs under Unix and Windows.