Although many open source enthusiasts have an almost reverent attitude towards technology, data center managers have specific business problems to solve, and judge technology only on how well it solves those problems. Let\u2019s examine the requirements that are specific to data centers and see if open source technologies can meet them.First, though, we should note that open source is not just Linux. Other open source operating systems include NetBSD, FreeBSD and Apple\u2019s Darwin, and there is a whole range of open source applications such as Apache (Web server), MySQL (database), OpenLDAP (directory), RADIUS (authentication), JBOSS (app server), sendmail\/cyrus (e-mail server).Data center managers evaluate technology on some of the following requirements:* Reliability - Open source technologies offer significant advantages over closed-source when it comes to reliability. The peer-review process of open source development means that bugs and security vulnerabilities can be fixed by anyone, not just the vendor. In a data center environment where the\u00a0operating system\u00a0can be customized and maintained by professionals, this is a critical advantage for open source.* Total cost of ownership - Linux is often cited as a lower-cost alternative to proprietary Unix systems. The lower TCO is a result of lower software licensing costs combined with commoditized and inexpensive hardware. For example, one of our clients reports a capital cost for database servers of $14,000 per server on Linux vs. $188,000 for Unix. Similarly, lower TCO can also be realized for other open applications such as Apache and OpenLDAP.* Flexibility - Linux virtualization offers flexibility for the deployment of computing resources. For example, IBM\u2019s latest eServer p5, announced July 12, uses Micro-Partitioning to offer 10 virtual operating systems on each server while also being able to re-distribute resources between partitions in less than one second. Linux can provide clustering features, symmetric-multi-processor support, grid computing tools and\u00a0operating system\u00a0partitioning, all of which can be combined to deliver \u201cutility computing.\u201d* Security - The ongoing debate about the relative security of open source (specifically Linux) vs. Microsoft operating systems is often reduced to the argument that the most \u201cpopular\u201d\u00a0open source\u00a0is bound to be targeted more - hence the rate of critical security vulnerabilities is higher on Windows. A quick look at the Web server market dispels that myth: Apache, with 67% of the Web server market (source: www.netcraft.com), has had 88 high- or medium-criticality vulnerabilities (source: icat.nist.gov), while Microsoft\u2019s IIS Web server, with only 21.32% of the market, has 112 high- or medium-criticality vulnerabilities.The advantages of open source technologies (and especially Linux) in the data center are numerous and compelling. Open source is mature, stable, secure and supported by most vendors, making it a viable data center platform. If you haven\u2019t considered open source in your data center strategy, now is the time.