The Sept. 11 terrorist attacks emboldened many outside the Muslim community to demand Islamic leaders re-examine religious teachings on matters from war to women's rights.
But in the United States, the latest call for reform is coming from within.
On Nov. 15, as the holy month of Ramadan is expected to end, a group of mostly young Muslims plans to launch the Progressive Muslim Union of North America in New York.
As their name suggests, the organization will take positions that conservatives consider objectionable, even heretical: Progressives believe women should have a broader role in mosques; they back gay rights; and they believe Muslims should borrow from traditions as varied as Buddhism and the U.S. civil rights movement to reshape Islam for modern times.
"When you've been taught ever since you can remember that Islam is a certain thing, especially as women ... you reach a certain point where it's not tenable anymore," said Sarah Eltantawi, 28, one of four founders of the Progressive Union. "People need to feel that there is an alternative Islamic space that has some legitimacy that they can turn to."
The organizers are taking significant risks with their platform.
Progressives intend to speak out publicly against Muslim practices they consider harmful, at a highly sensitive time when the community fears fueling prejudice against Islam. And by promoting acceptance of homosexuality and women's religious leadership, they leave themselves open to accusations that their agenda is not truly Muslim.
Sayyid Syeed, secretary general of the Islamic Society of North America, a leading Muslim organization in this country, warned that "creating forums and making them too radical" will alienate other Muslims.
"They might have something good on other issues," Syeed said, but their more controversial positions - on homosexuality, for example - will undermine their credibility.
"It will do a disservice," Syeed said.
Omid Safi, a religion professor at Colgate University and another founder of the Progressive Union, said the movement must take these chances. Progressives will not be "standing outside pointing an accusatory finger" at other Muslims; they want the religion to flourish, he said.
"We're trying to make it clear that this is somehow more than just a bunch of Muslim people who just happen to be socially progressive," said Safi, editor of the book "Progressive Muslims," which serves as a guide for the movement. "We're confronting a lot of problematic practices that are part of our faith and our community, while also admitting and acknowledging that there are incredible reservoirs of wisdom for us to draw upon from our faith."
The idea for the new organization grew from the Web site muslimwakeup.com. Ahmed Nassef, 38, a former marketing consultant and progressive activist who grew up in California, created the site with a friend about two years ago to find like-minded Muslims.
The site is anything but timid.
It openly criticizes major U.S. Muslim organizations for being too conservative and hosts discussion boards where Muslims debate the future of their religion. It also includes many provocative articles on topics such as Muslim women's sexuality, while running a "Hug a Jew," feature that profiles progressive Jews with a photo of them embracing a Muslim.
Muslim activists from overseas who cannot get their work published in their own countries often ask Nassef to post their writings on his Web site.
Muslimwakeup.com has quickly built a readership, reaching nearly 2.8 million hits last month, Nassef said. A few months ago, Progressive Muslim Meetup chapters grew from the site and now draw about 750 people for monthly gatherings nationwide, he said.
There are comparable progressive movements among Muslims in South Africa, Iran, Malaysia and elsewhere, that, like the American movement, include a critique of U.S. foreign and economic policies, and human rights abuses in Muslim and non-Muslim countries.
However, U.S. activists see something particularly American about how the ideas are spreading here.
The Muslim community in the United States is one of the most diverse in the world, encompassing Arabs, South Asians, Europeans and U.S.-born blacks. Among the thinkers the U.S. progressives are studying are the Rev. Martin Luther King Jr. and Elie Wiesel.
Yet, their chances for becoming a major influence in the United States are unclear.
Studies have found that the majority of U.S. Muslims are not active in mosques or affiliated with national Muslim groups. Nassef hopes they will find a home in the Progressive Union.
"Part of our mission as Muslims, as we see it, is to stand for justice in our community as well as critique what's outside of it," Nassef said. "As an American, I want to make sure that my country is doing what is right. As a Muslim, I want to make sure things are being done right in the name of our faith."