Does there exist any good programs to extract information on what hardware exists in the computer?
Like I would run it and I would get some info like this:

Proccessor: AMD Athlon blablabla
Display Adapter: GeForce 4 MX blabla
etc..

For Linux? just go Red Hat>System Tools>Hardware Browser. Simple.

Very low detaild information there.
No projects anywere? On sf.net or somewhere?

It would also be cool if I could run it in the command line.

you can try "lspci -v" to see information about your pci devices. registers for them are in /proc/bus/pci/.. (ex. "hex 0a.0" to get the register entries). for your cpu (also /proc/cpuinfo) and other info you can look at the "dmesg" output. it's generated at startup and tell's 'bout initaliazion of devices.
there are kernel modules (like lm-sensors) that are able to read hardwaresenors like fanspeed, (cpu)temperature,.. and if your board supports acpi and it's aktivated you can get information from the acpi-subsystem via /proc/acpi/.. there are, afaik, also graphical programs for some of them.
things about your graphic adapter can be viewed in ..pathtologfiles/XFree86.0.log. this file is generated everytime X starts up.


sl mritch.

"lshw" is a command line program you might be interested in.
Run as SU, it will list all the hardware you have, right down to bios version.
It is worth checking if it is already installed by default.