Why: Targeting cancer drugs narrowly to tumor cells will improve efficacy and reduce the side effects of chemotherapy.
Key innovation: Its delivery system uses engineered nanoparticles to deliver drugs to specific cells.
Why: It efficiently produces solar thermal power, which focuses sunlight to heat water into steam.
Key innovation: A boiler is heated directly with sunlight that bounces off mirrors.
Why: Its technology can reduce the cost of computing in data centers.
Key innovation: Runs servers with cell-phone chips rather than processors built on industry--standard designs, which are more power-hungry.
Why: Screening drugs on human heart cells will help researchers find treatments for cardiac problems and test drugs for toxic side effects.
Key innovation: Uses included pluripotent stems cells to make large numbers of heart cells for testing.
Why: Simple, fast diagnostic tests can help physicians track disease-related markers.
Key innovation: Its microfluidic device for doctors' offices can quickly detect elevated protein levels associated with prostate cancer.
Why: Web applications must get faster and feel much more responsive to users if cloud computing is to keep growing.
Key innovation: Its technology efficiently routes traffic across the Internet and makes websites faster.
Why: Corporate decision-making gets smarter if it taps the insights of rank-and-file employees.
Key innovation: Private prediction markets let employees forecast the results of corporate choices.
Why: Reducing the cost of constructing solar thermal plants will make them more competitive with fossil-fuel plants.
Key innovation: Software controls the mirrors that focus rays from the sun, eliminating the need to position them by hand.
Why: Social networking on the Web is becoming a powerful advertising medium and a platform for startups that offer add-on services.
Key innovation: Adapts quickly to shape its site into a medium that advertisers consistently want to use.
Why: New types of photovoltaics are reducing the cost of solar power.
Key innovation: "Thin-film" solar panels based on cadmium telluride, which are cheaper than conventional silicon panels, have made the company one of the world's largest photovoltaic manufacturers.
Why: Increasing the time that turbines are operational will lower the cost of wind power.
Key innovation: Co-developed a direct-drive wind turbine that eliminates the need for a gear-box. Having fewer moving parts reduces the chance of costly mechanical failure.
Why: By encouraging millions of people to sign up for quirky daily advertising e-mails, Groupon has created one of the fastest-growing revenue generators on the Web.
Key innovation: Offers local businesses a way to guarantee a return on their promotional budget, thereby tapping into a huge advertising pool that has eluded many Web companies.
Why: Computing can transform infrastructure such as electric grids and traffic control systems.
Key innovation: Is drawing on its research expertise and that of software companies it's acquired to develop services for many infrastructure industries and expand the market for information technologies.
Why: Biofuels could be far cheaper if they weren't made from corn, sugarcane, and other forms of biomass.
Key innovation: Designed microbes that convert carbon dioxide and water directly into fuels.
Why: Light-emitting diodes are an energy-efficient option for lighting in buildings and homes, but they are still expensive.
Key innovation: Its low-cost process produces LEDs on the same equipment used to make semiconductors.
Why: Augmented reality enhances the value of a mobile device, employing its camera and GPS and displaying information about the user's surroundings.
Key innovation: Its development platform lets businesses and advertisers add AR functions to their own apps.
Why: Computer chips that operate with probabilities instead of binary logic could speed applications such as fraud analysis and machine vision.
Key innovation: Its microprocessor uses electronic signals to represent probabilities rather than binary 0s and 1s.
Why: Biodegradable plastics that aren't made from petroleum offer several environmental benefits.
Key innovation: Its polymer-¬manufacturing processes use carbon dioxide to make plastics needed for packaging.
Why: User interfaces based on gesture recognition make possible new applications in gaming and everyday computing.
Key innovation: Developed the 3-D sensor system that Microsoft's Kinect device uses to track movement.
Why: Retrofitting existing buildings is a cost-effective way to increase energy efficiency.
Key innovation: Mass-produces windows with energy-saving features such as coatings and gas insulating layers.
Why: Improving the electric grid is crucial to making alternative energy sources less expensive.
Key innovation: Developed wind turbines and other technologies for different aspects of the electric grid, from generation to transmission to distribution.
Why: Computer intelligence in the electric grid will make energy distribution more efficient.
Key innovation: Developed hardware and software that standardize the way disparate parts of the grid communicate.
Why: Budget cuts will force NASA to rely on private companies for supply missions and other tasks.
Key innovation: Introduced a low-cost production method for everything from rocket engines to astronaut capsules.
Why: Expanding the use of mobile payments will help small businesses.
Key innovation: Built technology that lets anyone accept credit cards using smart phones.
Why: Extremely large-scale production of solar panels is reducing the technology's cost.
Key innovation: Developed its own solar cells and equipment for manufacturing them cheaply.
Why: Genetically engineered microbes are a promising way to make biofuels.
Key innovation: Created synthetic bacterial cells, possibly paving the way for organisms specifically tailored to make fuels.
Why: Conventional solar power is still too expensive to compete with fossil fuels, in part because of the cost of manufacturing silicon-based solar cells.
Key innovation: Developed a cheaper method for making silicon wafers, the most expensive component of a solar module.
Why: Now that the company has begun to make money from its large user base, a service that has woven its way into everyday life is more likely to stick around.
Key innovation: Its business model offers selected opportunities for advertisers while drawing income from deals that let search engines index its content.
Why: Web tools can help people respond to crises such as earthquakes and political protests.
Key innovation: Its open-source crowdsourcing tool overlays field reports on maps, providing critical and often life-saving data during emergencies.
Why: Companies are building businesses inside platforms like Facebook.
Key innovation: Its social games offer people a new way to interact.