From a business perspective, the purchase cost of software is only one factor; total cost of ownership (TCO) is what really matters. With other factors being equal, the solution with the lowest TCO is usually the most desirable one. Arguments in favour of low TCO for Open Source software include:

• Lower Purchase Price
• Potentially no need to account for copies in use, reducing administrative overhead
• Reduced needs for regular updates, giving lower or no upgrade fees and lower management costs
• Longer uptimes and reduced need for expensive systems administrators
• Near-zero vulnerability to viruses, eliminating the need for virus checking, data loss and downtime
• Lower vulnerability to security breaches and hack attacks, reducing systems administration load
• Ability to prolong the life of older hardware while retaining performance
• Better adherence to standards, permitting competition in the market and reducing vendor lock-in
• Availability of source code, providing greater continuity and security against the financial collapse of key product vendors and vendors choosing to withdraw support for unprofitable products
• Protection against being required to fit your IT strategy to the cash needs of your software supplier.

Organizations can only plan ahead in the long term if their IT environments permits them to do so. And it can only do that if provides flexibility and freedom. Software flexibility is about being able to choose solutions suitable for your businesses needs. Many commercial software products will claim flexibility as a built-in feature and some will be correct in that sense.

However, flexibility in a business context means business flexibility, so that as requirements in the business change, solutions should not be unreasonably constrained by software. This is especially important in the area of infrastructure components.

Open Source projects typically have very little motivation for any kind of lock-in strategy. It is usually free of any dependency on related products. This means that Open Source software offers its users a greater freedom to purchase other products, whereas commercial solutions often work best with other products from the same manufacturer.

Also, Open Source solutions give you the freedom to modify your software. You aren't limited to what one company believes you need. Proprietary software vendors must cater for many different companies, predominantly their own. Open Source software can be tailored for the way you do business. It is usually within the resources of all but the smallest companies to modify Open Source software to suit their own needs - and potentially make those enhancements available as a public good.

One of the most common counter-arguments to the use of Open Source software is the question of who is liable if the software doesn't work. What's usually not mentioned in this context is that most common software licenses for commercial products disclaim responsibility or liability for anything more serious than defects to the distribution medium. Proprietary software licenses are intended to absolve the vendor of liability for almost any problem you may incur.

In that respect, Open Source software does not differ from proprietary solutions. Open Source software licenses also typically disclaim all liabilities and warranties. However, most Open Source software users choose the practical benefits of increased reliability and security over illusory options to sue or pursue other remedies from a negligent vendor.

Another counter-argument against the use of Open Source software is that the free license to use the software does not include a support contract. But that counter-argument neglects the fact that many proprietary software licenses have no support included either. However, user of Open Source solutions can obtain training and support from third party Open Source consultants. It's always possible to retain a company to provide support. Because the source code is freely available, organizations are not limited to obtaining support from the authors.