Machinima is making movies within a real-time 3D virtual world either online or offline. Using the already created world and textures from a game make movie-making a lot easier than a 3d program. Most of these are made by well known games like quake, Wow and Halo. Others are made from online worlds like Sims Online or Second Life.
I found some which were made in Runescape. The graphics aren’t as good as the other platforms but some good story lines have been made. I personally like the movies with music and voices rather than trying to read the words. You can also see other movies from other platforms at machinima.com.