Some 100,000 people are expected to attend the third World Social Forum which opens in Porto Alegre on Thursday.
The World Social Forum 2003 has a packed agenda promising more than 1,500 different events hinged on the slogan "Another World is Possible."
The most debated topic will be that of the threat of war against Iraq.
A debate on how peace can be achieved despite that threat is scheduled for January 27 - the day UN weapons inspectors are due to deliver their report on their inspections in Iraq to the UN Security Council.
The forum is expected to draw 100,000 participants from 157 countries, including Brazil's new leftist President Luiz Inacio Lula da Silva.
Sources in Lula's government told a Brazilian newspaper that the new president would deliver the same anti-hunger and anti-poverty message to activists in Brazil and business and government leaders at a Swiss ski resort.
"The content of the message will be the same. But it's good to remember that the audiences will be different, so what might change is the tone used by the president," an unnamed government official told the O Globodaily.
After the discussion on Iraq, US political activist Noam Chomsky will give a talk, which is likely to be one of the most popular of the score of lectures offered at the Forum.
Last year, Chomsky severely criticized the military buildup after the September 11, 2001 attacks on the United States.
Three other discussion topics will cover governance in a post globalisation world, the world financial crisis and participative democracy, and will feature other well known speakers, including former Portuguese president Mario Soares.
AFP