HouTran was a public transportation company that served the Houston area. While its last iteration was publicly owned by the City of Houston, it was privately owned throughout the vast majority of its existence. Throughout several name changes and ownership acquisitions, the company's modes of operation ranged from mule-drawn streetcars to electrified streetcars, and finally to busses. In 1979, it was succeeded by the Metropolitan Transit Authority of Harris County, a state-authorized local transit authority, when it was purchased by that agency as the basis for its then new transit system.

Stone & Webster was an American engineering services company based in Stoughton, Massachusetts. It was founded as an electrical testing lab and consulting firm by electrical engineers Charles A. Stone and Edwin S. Webster in 1889. In the early 20th century, Stone & Webster was known for operating streetcar systems in many cities across the United States including Dallas, Houston and Seattle. The company grew to provide engineering, construction, environmental, and plant operation and maintenance services, and it has long been involved in power generation projects, starting with hydroelectric plants of the late 19th-century; and with most American nuclear power plants.