I read a collection of works by Karl Marx last year; let's see how much of it I actually absorbed.
Philosophically, as I saw it, Marxism was mostly about achieving happiness. Marx applauded true democracy, and condemned any system wherein people would have to stifle their own self, their own humanity, in order to survive; in this case, capitalism. He wrote a great deal about a worker devaluing himself by creating things, by investing himself in making things, which were not his, nor were they for him. He loses himself, as he only feels free to act on his animal needs--eating, drinking, procreating; in acting as a human, he is forced to subdue himself and work for another. The worker them becomes subservient to the products of his labour which allow him to exist, as they provide him with means for living.
In brief, he was upset at the thought that people would have to return to a job they hated day after day just to survive; in that regard, Communism would be a system which would provide for the people so that they could survive as humans, so that they could affirm themselves and not deny themselves. In practice, the government would have to own everything in order to distribute it, and most people seem to take issue with that. I'm not particularly politically savvy, so I won't get into the merits of communism beyond its base philosophy, but I will argue that in its base philosophy, it's beautiful.
EDIT: I'm American.