February Linux Shareware

Reviewed this month are Qcad, Nessus, Emacs and Xbill.

By Richard Keech

Despite the fact that Autocad isn't distributed in RPM format, Qcad installed very easily as a binary (making sure the the Qt libraries are installed and at least version 2.x). Only a draftsperson could fully appreciate all of its many features, but there are some that anyone can understand such as multilevel undo/redo, layers, snap functions and dxf functionality for standards-based drawing exchange.

Qcad comes with a great manual in HTML format; a request for help calls up your favorite browser and loads the manual into it. The menu structure was intuitive and the icons were clear and pleasing to the eye.

Printing worked without a hitch, required no special configuration and the output was clear and free of defects.

In many places it is evident that the software is in its early stages, but it is well packaged and mature for its age. Qcad has a very promising future -- it's definitely a worthy project for anyone considering contributing to open source.

Nessus' client-server arrangement provides some degree of control over who can perform checks. It has a sophisticated GUI (nessus) that talks to the back-end server (nessusd). There are Windows and Java-based client packages freely available, so control of the scan is independent of the host originating the scan.

Don't even think about using Nessus if you don't have authority from the owner of the host(s) you are scanning. Using security scanning tools is seen by many as an overtly hostile act that is sure to raise the ire of many a system administrator. As a means of detecting network vulnerability this package fits very well.

Configuration of both the client and the server are done during installation. The process is made easier by clear examples in the demo section of the Web site. The Nessus client program's user-friendly GUI program was built using the Gnome widgets.

Nessus has a clever plug-in capability that extends its ability to assess network vulnerability intelligently and stay up to date. Another strength is that you can limit its availability to specific users, which helps prevent non-privileged users from finding security breaches.

Emacs comes from the Free Software Foundation's GNU project. It was written and is still maintained by Richard Stallman, who started the free software movement in 1983. It would be hard to find a free software project more senior than GNU Emacs which is evident in version 20.4.

Emacs' capabilities are numerous, and if it doesn't do what you want then it has its own extensibility language called elisp that lets you program a large range of different functions. Emacs' core functions include: unlimited undo/redo; support for Asian character sets; arbitrary split screens (each window region can be split vertically or horizontally, as can each sub-window); both text and GUI-mode operation; and colouring of text and backgrounds.

Through the extensibility language many additional capabilities are provided in standard libraries such as: syntax-sensitive highlighting and colouring; integration with version control; integration with file management; integration with file differencing analysis; code compilation, execution and debugging environment; spellchecking; mail and news client; database front end; calendar and diary system; and application of code patches.

Emacs is much better suited to new users because it doesnÆt have viÆs infuriating, quirky moded behaviour. EmacsÆ extended capabilities and cursor movements are all accessed through control keys, but much of this can be done through the pull-down menus. A great plus for Emacs is the fact that many other programs in Linux use the same or similar key bindings. So you will find Emacs' cursor movement and simple editing capabilities showing up in unlikely places, such as the URL line in Netscape, the Bash shell and the pico editor.

Emacs capabilities are so rich and flexible that it is often used as a full-code development environment, and not just by those who can't afford a commercial equivalent. EmacsÆ usage has a depth and a width that makes it worth the effort to learn.

Multiple levels of difficulty increase the fun. If you use Xbill's wares on a networked PC, youÆll find that if you're not careful they will propagate across the network and infect other computers.

The only obvious detail thatÆs missing from Xbill is some gratuitously violent sound effects to accompany the splatter.