From the Brennan Center:

Almost every nationally-organized party that ran a presidential nominee in both 2012 and 2016 received more votes for President in 2016 than in 2012. That is definitely true for the Republican, Libertarian, Green, Constitution, Socialism & Liberation, Socialist Workers, and Prohibition Parties. It will probably be true for the Democratic Party, once all the votes are counted. The only exceptions are America’s Independent Party, the Socialist Party, and the Socialist Equality Party.

Some info on the Party for Socialism and Liberation:

The Party for Socialism and Liberation believes that the only solution to the deepening crisis of capitalism is the socialist transformation of society. Driven by an insatiable appetite for ever greater profits regardless of social cost, capitalism is on a collision course with the people of the world and the planet itself. Imperialist war; deepening unemployment and poverty; deteriorating health care, housing and education; racism; discrimination and violence based on gender and sexual orientation; environmental destruction—all are inevitable products of the capitalist system itself.