The advice given earlier in the thread about using ps to find all processes and then using Google to find out what they do is a good one. You'll learn lots of good stuff.

To write a script to kill off whatever you think is not needed is a less good idea. Many of the applications that are running are services that help other applications (and services) to perform specific tasks. If you kill one of them, you might very well make something else fail in ways that are not too easy to predict.

The general rule is to monitor CPU usage and how much RAM is available (and remember that Linux uses a disk cache to speed up disk access). If you haven't actively started any applications or installed something that's intended to run in the background to collect data locally or gather data from the internet, you're pretty much on the baseline.

Personally I think PulseAudio is a bit on the bulky side for a system like this but people have different needs.

When it comes to 150 processes sleeping, this takes up space in the kernel's internal tables but not much more. How much memory that has been allocated per process is something else. Just running X to get a display client and then placing GTK+/Qt on top of that takes a big chunk out of the system.

What it really comes down to is that Linux actually shows you EVERYTHING. Windows... not so much. It has as many back ground processes, but it won't show things like kthreadd, init, migration/0, ksoftirqd/0, watchdog/0, events/0 etc.

These are all kernel level services and wouldn't appear in Windows.

Rootkits can still hide themselves as other services, in Windows they tend to hide themselves all together. If you download some of the third party task managers you'd probably crap at how many Windows processes are actually running in the background that the standard task manager doesn't show.

Just remember that Linux is better because it doesn't run unnecessary processes in the background. It is nice in that it only does what you tell it.

slaapliedje

Do not worry about processes. Don't kill any. The exception is if there's a misbehaving process. So far I've only noticed that pulseaudio will (very very rarely) keep using CPU (10%-20%) even after all audio applications have terminated. That will kill the battery overnight. Killing it will automatically restart a new, well-behaving one. But that's the only process I would worry about. It hasn't actually misbehaved on me since I upgraded from 1.0 though.