Using a web browser, look for the open source and freeware intrusion detection tools listed in the chapter. next, identify two to three commercial equivalents. use the open source or freeware versions? what other expenses would the organization need to incur to implement this solution? 2. using a web browser, search on the term intrusion prevention systems. what are the characteristics of an ips? compare the costs of a typical ips to an idps. do they differ? what characteristics justify the difference in cost, if any? 3. using a web browser, visit the site what is this web site, and what does it offer the information security professional? visit the “know your enemy” whitepaper series and select a paper based on the recommendation of your professor. read it and prepare a short overview for your class.

Open Source Software / Free Software (aka OSS/FS), also described as Free/Libre and Open Source Software (FLOSS), has risen to great prominence. Briefly, FLOSS programs are programs whose licenses give users the freedom to run the program for any purpose, to study and modify the program, and to redistribute copies of either the original or modified program (without having to pay royalties to previous developers).

The goal of this paper is to convince you to consider using FLOSS when you’re looking for software, using quantitive measures. Some sites provide a few anecdotes on why you should use FLOSS, but for many that’s not enough information to justify using FLOSS. Instead, this paper emphasizes quantitative measures (such as experiments and market studies) to justify why using FLOSS products is in many circumstances a reasonable or even superior approach. I should note that while I find much to like about FLOSS, I’m not a rabid advocate; I use both proprietary and FLOSS products myself. Vendors of proprietary products often work hard to find numbers to support their claims; this page provides a useful antidote of hard figures to aid in comparing proprietary products to FLOSS. Others have come to the same conclusions, for example, Forrester Research concluded in September 2006 that “Firms should consider open source options for mission-critical applications”.

I believe that this paper has met its goal; others seem to think so too. The 2004 report of the California Performance Review, a report from the state of California, urges that “the state should more extensively consider use of open source software”, and specifically references this paper. A review at the Canadian Open Source Education and Research (CanOpenER) site stated “This is an excellent look at the some of the reasons why any [organization] should consider the use of [FLOSS]... [it] does a wonderful job of bringing the facts and figures of real usage comparisons and how the figures are arrived at. No FUD or paid for industry reports here, just the facts”. This paper been referenced by many other works, too. It’s my hope that you’ll find it useful as well.

The following subsections describe the paper’s scope, challenges in creating it, the paper’s terminology, and the bigger picture. This is followed by a description of the rest of the paper’s organization (listing the sections such as popularity, reliability, performance, scalability, security, and total cost of ownership). Those who find this paper interesting may also be interested in the other documents available on David A. Wheeler’s personal home page. A short presentation (briefing) based on this paper is also available.

This paper has become long, there is now a supporting database of OSS/FS (FLOSS) quantitative studies that you may find easier to use. You may also be interested in the discussion group for quantitative numbers about free / libre / open source software.

1.1 Scope

As noted above, the goal of this paper is to convince you to consider using FLOSS when you’re looking for software, using quantitive measures. Note that this paper’s goal is not to show that all FLOSS is better than all proprietary software. Certainly, there are many who believe this is true from ethical, moral, or social grounds. It’s true that FLOSS users have fundamental control and flexibility advantages, since they can modify and maintain their own software to their liking. And some countries perceive advantages to not being dependent on a sole-source company based in another country. However, no numbers could prove the broad claim that FLOSS is always “better” (indeed you cannot reasonably use the term “better” until you determine what you mean by it). Instead, I’ll simply compare commonly-used FLOSS software with commonly-used proprietary software, to show that at least in certain situations and by certain measures, some FLOSS software is at least as good or better than its proprietary competition. Of course, some FLOSS software is technically poor, just as some proprietary software is technically poor. And remember -- even very good software may not fit your specific needs. But although most people understand the need to compare proprietary products before using them, many people fail to even consider FLOSS products, or they create policies that unnecessarily inhibit their use; those are errors this paper tries to correct.