By Steve Kingstone
BBC South America correspondent in Porto Alegre
"Another world is possible."
The World Social Forum is five years old in 2005
This is the premise that underpins the World Social Forum (WSF), which takes place this week in the Brazilian city of Porto Alegre.
But what exactly does it mean?
"In reality, it's an umbrella slogan - to say that many other worlds are possible," says Fatima Melo, a WSF organiser who represents the Association of Brazilian NGOs.
"We believe that new worlds will be built through diversity and the pluralism of cultures. There can never be a single solution for countries as different as Brazil, Kenya, India and North Korea."
On the other side
In many ways, the WSF is best defined by what it opposes.
Namely, a global economy which is seen as putting profits ahead of people.
"We live in a world that's submitted to the interests of capital," says Chico Whitaker, a founder member of the WSF.
"Everything functions to make money - without thinking about people, unemployment and poverty."
The event's chief targets include the World Trade Organisation, multinational corporations, the International Monetary Fund and the World Bank. But what really motivates delegates is their distaste for the rival World Economic Forum - which takes place annually at a luxury ski-resort in Davos, Switzerland.
"At Davos, the politicians and bankers do lots of good business," Mr Whitaker says. "But they do nothing for the poor of the world."
The first event took place in 2001 and its meetings are deliberately scheduled to coincide with Davos.
This year's gathering is expected to draw at least 100,000 people from 119 countries.
Between them, they will take part in more than 2,000 debates and activities - loosely based on eleven campaigning themes.
Issues for discussion include free trade, land reform, human rights and climate change.
The most elaborate-sounding theme is called "ethics, cosmo-visions and spiritualities".
In their logistical planning, the organisers have remained true to the ethos of the forum.
Many of the venues have been built from traditional materials by members of Brazil's Landless Workers Movement (MST). Similarly, the computers in the media centre operate using free software.
Given its growth from an initial attendance of 20,000 four years ago, some have questioned whether the gathering has become too broad in scope.
The WSF sees itself as the 'anti-Davos'
Last October, Brazil's President Luiz Inacio Lula da Silva said the gathering "lacked focus" and risked becoming a mere "market-place for ideological products".
Lula argued that it could achieve more by focusing on a handful of flagship themes. Addressing the event this week, he will concentrate on the global fight against hunger and poverty.
Yet the organisers claim that many of its ideas have entered the mainstream.
They point to the fact that the Davos agenda for 2005 features such themes as "socially-responsible investment" and "equitable globalisation".
"Many of our approaches have been incorporated by Davos and by institutions like the World Bank," Fatima Melo insists.
"But here, we follow a genuinely different system of social relations. With their multinationals and financial institutions, we think Davos is far from achieving what we have here."