While debugging a weird Carmen behavior recently, I noticed that some of the included programs would stall on startup if I had quit them shortly before. After some time in the debugger, I narrowed it down to the seeding of the random generator where /dev/random is accessed. Interestingly, read calls to /dev/random stall until enough entropy is accumulated. If you do not want this behavior, /dev/urandom is available which won't stall waiting for more entropy from physical events at the cost of reducing the quality of the random number stream. Another good thing to know!