Inkscape is a mature SVG vector graphics editor. You can run it on a number of platforms including GNU/Linux and Windows. It has a rich set of features and is popular and actively maintained. The Book of Inkscape: the definitive guide to the free graphics editor, by Dmitry Kirsanov is a comprehensive guide of 476 pages that describes in detail the various parts of the software. The book also includes six chapter-size tutorials that emphasis the manipulative power of this feature rich editor.

The C language, despite the best journalistic assassins, trained monkeys on bikes, an alleged lack of fashion taste, is still alive and rocking in the building. C is, beyond dispute, recognized as a resource efficient and thus valid language to use, especially for highly effective operating systems such as GNU/Linux and for device driver creation. A good starting point for learning is K N Kings popular book "C Programming: A modern approach", published by Norton, which has just reached its second edition and hence worthy of a new review.

Ruby is currently one of the most fashionable and modern languages to program in. Ruby is synonymous with the Rails framework, which is a robust and deep framework used to prototype and then build stable and scalable web applications. Of course, Ruby has considerable potential in its own right. The book "Ruby by example, concepts and code" by Kevin C. Baird and published by No Starch Press will help you to learn the Ruby language via small incremental example scripts.

Plone is a well-known Content Management Systems (CMS). Since it's relatively easy to customize to a specific enterprises style and workflow, there is a healthy trade of services around the core software. Martin Aspeli, the book's author, is an active contributor to Plone. Heavy involvement in a project that you are writing about always bodes well for the potential value and quality of a book that you, the reader might be considering buying. Aspeli's book "Professional Plone Development", published by PACKT, proves this quality point once again.

Perl is an amazingly powerful and succinct language. Although not the most fashionable, Perl is consistent and supported on a vast range of platforms, probably even more than Java. Better still, it gets in and does the job quickly with very little fuss. Perl by Example written by Ellie Quigley and published by Prentice Hall is a comprehensive, example based, and thorough book.

The stability of an enterprise-wide infrastructure depends on understanding innovative, defensive security-related software. Linux Firewalls: Attack Detection and Response with iptables, psad and fwsnort written by Michael Rash and published by No Starch Press, outlines viable approaches that enable a defensive solution in depth.