the World Social Forum (WSF), meant as a counterweight to the World Economic Forum of political and business leaders that will begin January 21 in the Swiss ski resort of Davos.
On the eve of the six-day forum, hundreds of activists and journalists wandered the sprawling exhibition grounds as crews of women in bright red sarees broomed away the dust from the construction work.
With journalists speaking a myriad of languages inquiring about the center they would use to file their stories, a young Indian volunteer wrote a sign: "Media center not officially functioning yet."
Her superior told her to write it again.
"Do you have to write 'officially'?" he told her. "There's nothing official about the WSF. You don't have to talk like a state."
More than half of the participants at the WSF are from host India, as the anti-globalisation movement tried to branch out from its European and Latin American roots. The WSF was held in the Brazilian leftist stronghold Porto Alegre in 2001, 2002 and last year.
Among the delegates in Mumbai are around 500 Tibetans, whose spiritual leader the Dalai Lama lives in exile in India.
Tibetan activists will "look to form a solidarity network with Palestinians, Kurds and others", explained Passang Dolma, general secretary of the Tibetan Women's Association, sitting next to three nuns who will hold an exhibition here of mandalas, or religious paintings.
Among the scheduled speakers at the World Social Forum are Shirin Ebadi, the Iranian rights campaigner and 2003 Nobel Peace laureate, Yossi Beilin and Yasser Abed Rabbo, the Israeli-Palestinian team that drafted the unofficial Geneva peace plan, and Jose Bove, the radical French sheep farmer and symbol of the anti-globalisation movement.
Several activist groups plan attention-grabbing arrivals, including Japanese pacifists whose "peace boat" is due to dock in Mumbai on Thursday and hundreds of low-caste Hindus whose nationwide march is expected to culminate at the WSF grounds Friday.
But for most already here, the WSF is as much about enjoying a show of characters and exploring Mumbai, a metropolis of 18 million people that is home to glitzy Bollywood and massive slums and ruled by the Hindu extreme-right.
WSF participants swapped backpackers' guides on the lawn, with many of the polyglot conversations focused more on the practicalities of taking buses and trains than on the direction of leftist causes.
"The WSF is important as a counterweight to the World Economic Forum and India is a great place to raise awareness as it hasn't been completely touched by capitalism," said Jose Menindez, an anti-globalisation activist from Spain.
"We're here to build contacts, but also to have fun, to explore a diverse, multilingual county," he said.
Ilona Moore, a student from the United States, had been researching development issues in Bangladesh and then travelling around India when she decided to head to the WSF.
"I just wanted to see what was going on, as there are so many people here working on so many different issues, and this relates to what I'm studying," she said.
The last WSF turned into a rallying ground for opponents of the imminent US-led invasion of Iraq and the tone has not changed, with South Korean activists greeting early-comers to the Mumbai meet with pamphlets urging "Stop Bush".
Concerns about US policy led organisers not to seek funding from the Ford Foundation, which contributed half of the money for the last WSF gathering in Porto Alegre, said WSF spokesman Gautam Mody, an Indian labour organiser.
But the move was not enough for the far left, which is holding a rival "Resistance 2004" down the street and has spray-painted under dozens of Mumbai bridges: "Globalisation cannot be humanised. It must be destroyed."