Wikipedia says "It is difficult to tell how much of what people write in these venues is serious, and how much is intended to provoke outrage."

It's got a lot of press since President Elect, Trump appointed Stephen Bannon, his campaign chair as his top senior advisor.
Bannon has described his Breitbart News Network as "the platform for the alt-right".

Terms:

Antifeminism/Masculinism

Antisemitism

Ethno-nationalism

Homophobia

Islamophobia

Memes - An element of a culture or system of behavior that may be considered to be passed from one individual to another by nongenetic means, especially.
Internet memes are a subset of this general meme concept imitation.

Nativism

Neo-monarchists

Neoreactionary movement

Nihilists

Right-wing populism

Traditionalism

Trolls - In his New Yorker article "Trolls for Trump", Andrew Marantz refers to people from the Alt-right who post twitter messages with hash tags like "#ZombieHillary" and "#HillarysMigrants" where they reminded people that people like Remind people that Angela Merkel and George Soros were friends.
Mike Cernovich's #DrunkHillary video on periscope feeding the rumor that she has seizures got 23,400 views.
#maga on Twitter has 5 million views and a lot of Alt-right tweets.

White supremacism

Web Links:
The Alt-Right Hails Its Victorious God-Emperor - The New Yorker
Trolls for Trump - The New Yorker
The Trump Phenomena: Who loves Donald Trump? | Currency Solutions
Twitter suspends major alt-right accounts - The Verge