Hardware

Q. What's the minimum system spec to run MPD?
A. Users report easy success with a using RedHat on a 120mhz Pentium, 32mb of RAM and a 2.1G hard disk. Others have used 75mhz Pentiums with 48mb of RAM.
Generally running on minimal hardware you have two issues: CPU performance and swapping. You can avoid swapping by minimizing what else runs on the system, compiling a smaller kernel and things of that sort. CPU performance on a P75 is very close to the minimum - you need to compile with the correct optimizations:

export CFLAGS="-O2 -ffast-math -mpentium" 
./configure --with-mpd-mad 
cd src/libmad 
./configure --enable-speed 
cd ../.. 
make

Also, mad maybe able to efficiently run on your system, and flac should as well, but i'd be suprised if you could play oggs on that system.

Q. This is great but I don't want a PC in my living room!
A. You have several basic choices:

Buy an inexpensive laptop
Buy a moderately priced "mini PC" such as the XPC line from shuttle
Put the MPD box in another room and run some kind of audio distribution

Q. The sound on my XYZ computer is terrible. What can I do?
A. Laptops and build in audio hardware are generally low quality. Consider a USB sound card.

Q. This is great. How can I put it in my car?
A.

Q. I have one MPD box and 3 stereos and want to play the same audio on each.
A. You have two basic types of solutions: audio/video solutions and computer solutions. Then there's the choice of wired versus wireless. Even as someone with 20 computers in the house and two wireless networks I favor the wired AV solutions so this answer is slightly biased.
Computer solutions all involve a PC at each stereo and streaming the content to the PC over a wired or wireless network. The downside is this eats bandwidth, requires software setup on each PC and you usually have difficulty getting playback synchronized.
For the AV choices you again have wired and wirless choices. For wireless you buy a set of wireless AV transmitters from SmartHome and run them between the MPD box and your stereo(s).
For AV wired there's two good possibilities. First is the obvious one - buy a splitter and run line-out from your MPD box to each stereo.
And finally my favorite. Buy a wired AV modulator/amplifier from SmartHome and use your existing cable TV wiring. A good modulator/amplifier is the ChannelPlus which has two sets of RCA inputs, 2 short run outputs and 3 long run outputs. This is also a nice way to "share" a ReplayTV or other AV component like a digital cable box across all your TVs. The IR distribution option is expensive ($60 per IR target) but would let you control the MPD box and your other components
Q. How can I use a remote to control MPD?
A. See the mpd-lirc-miniHOWTO. Another choice is to use an X10 controller and Xtend.

Software

Security

Q: Is it possible to make MPD more secure?
A: By default MPD binds to all addresses, thus allowing anyone to connect to MPD and manipulate MPD. There are two options to making MPD more secure. One is to set "bind_to_address" option in the mpd config file (an example config file is provided with the MPD source and there is an example in the MPD man page). For example, to only allow connections for localhost host, set "bind_to_address" to "localhost". Other options include:

Enable password authentication. Please read the mpd man page for more info on enabling password authentication.
Use iptables or ipchains.
Use stunnel to wrap MPD and possibly require client side certificates

Database

Q: My db is corrupted, how do I fix it?
A: Run mpd with the "--create-db" option. This will recreate the mpd db from scratch.

Q: How do I update the db?
A: With phpMp click the update link on the bottom of the main page, with mpc just type "mpc update".

Q: How big are the db files?
A: