There are currently 222 public schools in "13 foreign countries, seven states, Guam, and Puerto Rico" (DOD).
Costs to participate as a volunteer vary depending on the organization, the country and the length of the program.
Volunteers most often teach English but other subjects can also be covered, such as computer skills, AIDS/HIV awareness, science, math, etc.
Some countries with prominent English teaching programs are Chile, Spain, France, and Georgia.
[3] Programs are organized by individual schools, national governments (such as the JET Programme in Japan and English Opens Doors in Chile).
Many English language schools and companies in China, in recent years, have moved to a strategy more adaptive to this market pressure, and have started employing thousands of teachers around the globe to teach through online teaching, giving quick rise to the new industry of online teachers.