• What is open source?
• What is open source? Why use open source?
• Why not to use open source
• How should I get started with open source?
• Server apps are fine, but what about open source on the desktop?
• Can I sell open source-based products?
• Other open-source resources

The success of open-source software has been remarkable, forcing even the largest commercial software vendors such as IBM , Hewlett-Packard , Oracle and Microsoft to acknowledge its influence and, in some cases, adopt its methods. It seems likely that most companies with information technology departments of any size are familiar with — if not actively using — open-source products on a daily basis.

But its ubiquity can lead to more questions than answers. Here, therefore, are the answers:

What is open source?

Back in 1997, Bruce Perens, a prominent Linux operating system developer, wrote a document concerning the distribution and development of the Debian Linux distribution. He later removed references to Debian and created what is now known as new. Among other things, the Definition states that open source software must be distributed without royalty, that the distributor must make the source code for the software freely available, and the derivative works from the code must also be released as open source.

Open source is essentially a cousin of the Free Software Movement, created in 1983 by Richard Stallman to promote the free distribution of software unfettered by standard proprietary code restrictions. Free software's rules are codified by the General Public License (GPL), which as of October 2006 was under review for its third revision.

There are literally dozens of Open Source Initiative certified licenses, each with its own peculiar rules that require close examination by any company looking to use open-source software. These rules are usually quite generous for anyone who merely wishes to use open source software. The requirements for redistribution, however, can require careful scrutiny to avoid potential license violation issues.

Why use open source?

The first reason many companies begin looking at open-source software is simple: price. And the return on investment of the open-source model has been clearly demonstrated. Open-source software can be downloaded, installed and operated free of charge. In its early days, this low cost made it a tempting option for developers interested in trying new tools or building new applications but without the budget to do so. This freedom led many developers to start contributing to the open-source movement, resulting in such industrial-grade software as the Linux operating system, Apache Web server, JBoss Java application server and Eclipse development environment — among thousands of other projects.

It wasn't until the late 1990s, however, that corporations began noticing open source at the executive level. With developers touting the quality and cost savings of using open source, and with IT budgets under constant pressure, many large companies began investigating open source for enterprise projects. Early large-scale adopters included The Weather Channel, Cendant Travel, and Employease and Sabre.

Especially during the heavy growth of the Internet, open source let companies quickly ramp up their online operations without the need to constantly buy new licenses for commercial software. This scalability also lent itself to development and test environments, reducing the cost to simply try new things without the added drag of commercial software pricing — and the mandatory budgetary process — getting in the way.

Perhaps not surprisingly, the fact that the source code is available for open-source products is usually not a big draw. While having the right to modify or fix code at will is certainly seen as a plus, many companies find that they'd rather not get into the habit of maintaining the code themselves, instead depending on the community of developers that exists around popular products to keep the code up to date and debugged.