A site commemorating the 150th anniversary of the publication of the Communist Manifesto.
http://easyweb.easynet.co.uk/~socappeal/150years/
The site contains the complete text of the Manifesto as well as two essays, one by Leon Trotsky and one by Alan Woods, considering the enduring legacy of this seminal work.
This site is dedicated to "defend[ing] Marxist ideas and their validity for today's labor movement."
It is provides a contemporary Marxist perspective on a number of world events and is invaluable for anyone interested in how Marxism has survived the collapse of the Soviet Union.
This site is a wonderful resource on Marx and Engels.
http://www.marxists.org/archive/marx/index.htm
It provides the complete texts of all Marx's and Engel's major works, as well as less known publications and personal correspondence. There are also several biographies of each thinker, complete with an excellent image gallery.
This site brings together significant writings in the development of Marxism from Marx to our own day.
It is a good resource for examining how Marx's views have been applied to circumstances he could not have imagined in the middle of the 19th century.