Egyptian President Hosni Mubarak's government is being rocked by a second week of protests, which neither the military nor the police have been able (or willing) to crush. The "loosely unified opposition" consists of a variety of groups, with representatives set to meet Monday to develop a combined strategy for forcing out the longtime leader. The organizers behind the uprising are also planning a "march of the millions" Tuesday to increase pressure on Mubarak. Here, a look at five key players in the uprising:

1. Mohamed ElBaradei
The Nobel laureate and former head of the International Atomic Energy Agency is now widely seen as the consensus leader of the opposition. His umbrella group, the National Association for Change, has spent the past year trying to unite opposition factions around demands for new elections, and his curfew-defying appearance and megaphone-broadcast speech in Tahrir Square on Sunday "gives him street cred he needs" with the protesters, says New York Times columnist Nicholas Kristof on Twitter. ElBaradei predicts Mubarak's fall in "the next few days." (Watch a CNN interview with ElBaradei)

2. Internet-savvy 20-somethings
The April 6 Youth Movement, made up of Internet-fluent Egyptians under 30, organized the first mass protest on Jan. 25 via social media sites. "The public here mocked those young people who had taken to Twitter and Facebook to post calls for protest," says Egyptian author Mansoura Ez-Eldin in The New York Times. But the "cynics — myself included" — aren't laughing anymore. Even after ElBaradei's group and other established opposition leaders joined in the protests, "the same handful of young online organizers were still calling the shots," say David D. Kirkpatrick and Mona El-Naggar in The Times.

3. Al Jazeera
The Egypt uprising is certainly a case study in "the role of social media in sustaining the protests," and organizing them, says George Winslow in Broadcasting & Cable. But the focus on "new media" does not tell the whole story, says Marc Lynch in Foreign Policy. Old-media cable network "Al Jazeera may be so 2005," but not only has the top Arab media outfit let protesters (and the outside world) know what's going on, the "'Al Jazeera narrative' of an Arab public challenging authoritarian Arab regimes" made the uprising possible in the first place.

4. Muslim Brotherhood
A little slow to the party, the Islamist Muslim Brotherhood — the largest opposition group in Egypt — is playing a larger role in the protests, according to global security analysts Stratfor. Mubarak is trying to split the opposition by playing up fears of a Muslim Brotherhood–led "theocratic dictatorship," says Juan Cole in Informed Comment, but that's a "desperate ploy and unlikely to work." Mainstream Egyptians and Coptic Christians do fear the Brotherhood, but "their dislike of the Mubarak government for the moment seems to overcome their anxieties about a theocracy."

5. Soccer fans
Seriously, "hardcore soccer fans" could be the "unsung heroes of Egypt's uprising," says Adrien Chen in Gawker. "These guys are better at tangling with cops than just about anyone," and it wouldn't be the first time soccer and political unrest have mixed. So far, in fact, "the ultras — the football fan associations — have played a more significant role than any political group on the ground," said Egyptian blogger Alaa Abd El Fattah on Al Jazeera. Given the blue-collar grit and passion of "organized soccer fans," this is "every Arab government's worst nightmare," says James Dorsey in Bleacher Report.