Challenges to our business model may reduce our revenues and operating margins. Our business model has been based upon customers paying a fee to license software that we developed and distributed. Under this license-based software model, software developers bear the costs of converting original ideas into software products through investments in research and development, offsetting these costs with the revenue received from the distribution of their products. In recent years, certain “open source” software business models have evolved into a growing challenge to our license-based software model. Open source commonly refers to software whose source code is subject to a license allowing it to be modified, combined with other software and redistributed, subject to restrictions set forth in the license. A number of commercial firms compete with us using an open source business model by modifying and then distributing open source software to end users at nominal cost and earning revenue on complementary services and products. These firms do not have to bear the full costs of research and development for the software. Some of these firms may build upon Microsoft ideas that we provide to them free or at low royalties in connection with our interoperability initiatives. A prominent example of open source software is the Linux operating system. Proponents of open source software continue efforts to convince governments worldwide to mandate the use of open source software in their purchase and deployment of software products. Although we believe our products provide customers with significant advantages in security, productivity, and total cost of ownership, the open source software model continues to pose a significant challenge to our business model. To the extent open source software gains increasing market acceptance, sales of our products may decline, we may have to reduce the prices we charge for our products, and revenue and operating margins may decline.
Another development is the software-as-a-service business model, under which companies provide applications, data, and related services over the Internet. Providers use primarily advertising or subscription-based revenue models. Recent advances in computing and communications technologies have made this model viable and enabled the rapid growth of some of our competitors. We are devoting significant resources toward developing our own competing software plus services strategies. It is uncertain whether these strategies will be successful.
We face intense competition. We continue to experience intense competition across all markets for our products and services. Our competitors range in size from Fortune 100 companies to small, specialized single-product businesses and open source community-based projects. Although we believe the breadth of our businesses and product portfolio is a competitive advantage, our competitors that are focused on narrower product lines may be more effective in devoting technical, marketing, and financial resources to compete with us. In addition, barriers to entry in our businesses generally are low and products, once developed, can be distributed broadly and quickly at relatively low cost. Open source software vendors are devoting considerable efforts to developing software that mimics the features and functionality of our products, in some cases on the basis of technical specifications for Microsoft technologies that we make available. In response to competition, we are developing versions of our products with basic functionality that are sold at lower prices than the standard versions. These competitive pressures may result in decreased sales volumes, price reductions, and/or increased operating costs, such as for marketing and sales incentives, resulting in lower revenue, gross margins and operating income.
We may not be able to adequately protect our intellectual property rights. Protecting our global intellectual property rights and combating unlicensed copying and use of software and other intellectual property is difficult. While piracy adversely affects U.S. revenue, the impact on revenue from outside the U.S. is more significant, particularly in countries where laws are less protective of intellectual property rights. Similarly, the absence of harmonized patent laws makes it more difficult to ensure consistent respect for patent rights. Throughout the world, we actively educate consumers about the benefits of licensing genuine products and obtaining indemnification benefits for intellectual property risks, and we educate lawmakers about the advantages of a business climate where intellectual property rights are protected. However, continued educational and enforcement efforts may fail to enhance revenue. Reductions in the legal protection for software intellectual property rights or additional compliance burdens could both adversely affect revenue.