Research firm Gartner estimates that 80 percent of all commercial software will use open source by 2012:
"By 2012, 80 per cent of all commercial software will include elements of open-source technology," Gartner wrote in a report. "Many open-source technologies are mature, stable and well supported. They provide significant opportunities for vendors and users to lower their total cost of ownership and increase returns on investment. Ignoring this will put companies at a serious competitive disadvantage. Embedded open-source strategies will become the minimal level of investment that most large software vendors will find necessary to maintain competitive advantages during the next five years."
Open-source technologies are already broadly used across the entire spectrum of the software industry, which means that Gartner's guess looks like a safe bet. The research firm is primarily referring to developer-oriented software components that are distributed under permissive open-source licenses—such as the BSD license and GNU's Lesser General Public License (LGPL)—that broadly permit inclusion of licensed source code in proprietary software and do not mandate the broad reciprocity requirements that are found in popular copyleft open-source licenses like the regular General Public License.