I'm completely new to Linux and I'm just trying to understand where all my RAM is going. I've got a pretty fresh install of Xubuntu running as a VMWare guest, and I've given it 1.5GB RAM to play with. After only running two apps starting up Tomcat servers and also running Firefox, I've got hardly anything left. 160MB according to free -m. Looking at the output from Top, I see Java appearing twice, each stealing about 1/2 Gig resident memory. Both Tomcat instances use the same jdk, I would have thought I'd only see Java there once. What's the story? I had a screenshot but unfortunately couldn't post it being under 10 rep. Update The free -m output requested: total used free shared buffers cached Mem: 1419 1380 39 0 8 111 -/+ buffers/cache: 1259 160 Swap: 509 68 441 Top (coming)