Short answers, pulled from the story.
The Kampuchean United Front for National Salvation was founded on the 2nd of December 1978, at a meeting of seventy dissident Cambodians in Kratié Province near the Vietnamese border. The gathering was called a "Reunion Congress" by Khmer socialist militants.
Heng Samrin was voted chairman of the Salvation Front at its founding congress on the 2nd of December 1978. Chea Sim served as vice president and Ros Samay as secretary general.
The Salvation Front legitimized the Vietnamese invasion of Cambodia by providing a Cambodian political organization opposed to Pol Pot's government, precipitating the defeat of the Khmer Rouge's Democratic Kampuchea regime and the establishment of the People's Republic of Kampuchea.
The Salvation Front was renamed the Kampuchean United Front for National Construction and Defence in 1981. On the 29th of April 2006, at its fifth congress in Phnom Penh, it was renamed again to the Solidarity Front for Development of the Cambodian Motherland.
The Kampuchean Revolutionary Women's Association claimed 923,000 members as of October 1983. It was one of several large mass organizations affiliated with the front.
The Salvation Front was a pro-Hanoi umbrella organization that legitimized the Vietnamese invasion of Cambodia. Its cadres were specifically tasked with conducting "activities of friendship" to foster cooperation with the Vietnamese people, army, and experts based in Cambodia.