Wanted: a Prius for the delivery industry

At ‘AltWheels’ expo, inventors bring the hybrid mind-set to gas-guzzling shipping trucks.

How white roofs shine bright green

Painting homes a lighter shade does more than save money on A.C.

O3b Networks: A far-out plan to deliver the Web

Are 16 satellites the answer to reaching 3 billion people?

Jhai PC: Low-cost computer links villages to the Web

Rugged Internet portal designed for Laos now attracts interest in 65 countries.

How to download free books, music, and movies from local libraries

Bookmobile teaches people ways to digitally tap into the next phase of book lending.

Obama-McCain contest: Should winner of popular vote always win the White House?

National Popular Vote initiative would change how states cast Electoral College votes.

New rays of hope for solar power’s future

High cost of fossil fuel and advanced technology improve this energy source’s prospects.

Designs for a better world emerge from M.I.T. summit

Diverse teams brainstorm and build simple solutions to help developing nations.

Ship emissions: sizing up a big problem

Better way to recycle computers

Buildings designed by termites

Program helps Arizona prisoners get ready for real life

From Day One, inmates are treated like adults, lowering the chance they will return.

A water pump for the people

Inventor Martin Fisher designs easy irrigation tools for African farmers.

Can plug-in hybrids ride to America’s rescue?

The engineer behind many electric-car advances says oil’s days may be numbered.

Online tales of everyday heroes

New website seeks to inspire kindness by promoting past good deeds.

The field narrows for e-books

As Microsoft backs away from digitizing old texts, some worry that a single company could privatize world knowledge.

BP creates a greener place to pump gas

A filling station from the future lands in Los Angeles.

Politics on Facebook brings trouble for young Egyptian

Ahmed Maher says he was arrested and tortured by Egyptian authorities for starting a group on the popular social-networking site that was intended to support a nationwide strike.

Study abroad through Second Life

Virtual college campuses host international student exchanges.

Hurricane drones