The New People's Army is the military arm of the Communist Party of the Philippines. It generally follows the Maoist ideology. Formed in 1969 soon after the CPP was re-established, it commanded nearly 10,000 armed fighters at the height of its operations during the Marcos years. It primarily operates on the island of Luzon and the Visayas islands. It has fought the Philippine government for over thirty years, although is now losing members with the collapse of global communism.
The NPA primarily operates in rural areas, although it does maintain some cells (like the Alex Boncayao Brigade) in Metro Manila and other large cities. It opposes all US or Western influence within the country (all its propaganda deal with "resisting the US-(insert current President name) regime"), and has conducted several attacks on US military interests (although few on actual American citizens) before the US bases pulled out in 1992. It has since then indicated its intention to attack any US troops entering the country under the 1999 Visiting Forces Agreement.
It actively recruits from many college campuses, especially from the University of the Philippines. Officers are usually ex-college students, while the troops are recruited from dispossessed farmers and other rural poor. On college campuses, the expression "namundok" is used to describe a student who has "gone to the mountains" and has joined the CPP-NPA.
They seem to have little influence over the urban poor, although they have worked closely with the Kilusang Mayo Uno and other militant labor organizations.
The collapse of the Soviet Union, as well as China's increasing capitalist shift has brought forth several schisms within most leftist organizations in the country. Several groups have split off from the NPA, including the ABB, the Rebolusyong Partido ng Manggagawa - Pilipinas (RPM-P), and others.
The amnesty granted by recent administrations has also helped in reducing the numbers of the NPA; several prominent leaders have already returned to Philippine society, and in many cases, have even started to work within the system by running for office.
The CPP and the NPA are currently taking part in the peace talks in Oslo, Norway with the Arroyo administration, which are not expected to be concluded before next year.
Facts checked from www.fas.org, web.nps.navy.mil, and the Philippine Daily Inquirer. Several of my friends have joined the NPA (and have since returned), and a few have lost parents or other loved ones in the cause.