PVDA is the best thing Belgium has going, but it’s pretty much the same as the SP used to be 10-15 years ago in the Netherlands. They are bureaucratic social-democrats, with only a minority of the party being made up of marxists.
There’s still MLs in the Netherlands, they are in the CJB (Communist Youth Movement) though.
ROOD doesn’t believe in a bloodless revolution, by the way. It was one of the things they got attacked for in the media (in favour of things such as arming the masses).