Will my hardware be able to run DirectQ?
If you've upgraded at any time within the last 8 or so years then the answer is "very probably, yes". DirectQ requires full Direct3D 9 class graphics hardware, with support for vertex and pixel shaders, so this is the baseline you need to shoot for. Note that if you're a GeForce FX user you may experience very poor performance as these cards are notoriously bad with full precision floating point.
The main reason is simple: the drivers are often better. This is particularly the case with Intel and ATI/AMD hardware (although the latter does improve over the years). It's also nice to have Direct3D available as an alternative for people. Plus I wanted to learn Direct3D, and this seemed a cool way of doing so.
What version of DirectX do I need?
DirectX 9 is the one. Note that updates to DirectX 9 have been made available since both DirectX 10 and 11 were originally released, so even if you're on one of these versions you might still need a DirectX update (updating DirectX 9 won't affect your installation of either DirectX 10 or 11). Please make sure that you download this update directly from Microsoft rather than some dodgy third-party DLL-finder site (I'd hate to see you risking malware on your PC).
I have Intel Graphics. Can I run DirectQ?
Very probably. DirectQ was originally developed to run well on Intel graphics, and still does. You will need at least an Intel 910/915 (earlier models are not D3D9 class), and you will probably find that it runs substantially faster than any alternative. I'm particularly fond of the Intel 945, which is an excellent performer.
What about Windows versions?
You'll need at least Windows XP to run DirectQ. You might be able to get it running on Windows 2000, but I make no promises. It will not run on Windows 98 or earlier, and as I no longer have a Windows 98 installation to test on this will remain the case. DirectQ runs perfectly on Windows Vista and 7 without needing any compatibility hacks (so don't use them, and if you do I'm not responsible for anything bad that happens).
And what about other hardware requirements?
So long as your PC isn't a dinosaur-era piece of junk you should be fine. If you can run Windows XP or higher well enough, DirectQ shouldn't present any problems, so long as you meet the 3D hardware requirements.
What do I do if DirectQ crashes?
Despite my best efforts, DirectQ may sometimes crash on you. You can report this to me either by posting a comment on one of my blog entries, or by dropping me a PM on either QuakeOne.com or Inside3D (I'm the user "mh" on both). You should try to describe what happened, what you were doing when it happened, and if you got any error messages what the full text of the error message was. Sometimes I might know the cause and be able to get you a fix (which will be included in future versions) quite quickly, sometimes I might ask you to try a few different things out, and sometimes I might need to send you test builds for further investigation. Unfortunately, sometimes I might not even be able to fix it at all (I try not to let that happen too often).
How can I make DirectQ faster?
There are several hacks and settings you used to need in GLQuake to get better performance in certain circumstances, including disabling multitexture, running in 16-bit modes, gl_ztrick, etc. These have carried over to some other source ports, but DirectQ is immune to the problems that made these necessary.
How do I find out what cvars and commands are available?
In common cases these are available via menu options, but you may prefer to use the console or need the names for a config file. I've also cvar-ized a lot of what were previously hard-coded "magic numbers" in the engine. The "cvarlist" and "cmdlist" commands are your friends. I also maintain a page on this site giving the full lists, as well as occasional brief explanations, but I don't update this as often as I should.
Tell me about mod support?
One objective of DirectQ is to give you a good gameplay experience in as many mods (both SP and MP) as possible. You'll find the usual common features here, such as external textures, large map support, game changing from the console, as well as a few "specials", such as extremely high performance in complex scenes. If you think you've encountered a bug with a mod, and if it's reproducable, then by all means let me know (via the same channels as for crashes) and I'll check it out.
Will you add Feature X to DirectQ?
It depends. So long as it fits in with the general high-level goals of DirectQ (to be a tolerably faithful, high performance general purpose Quake client) it's a candidate. If it doesn't conflict with other features that I might deem to be more important, if it's not a performance drain, if it's not of quite marginal interest, if it tickles my own interest in some way, or if you can make a good argument for why this feature would be desirable, it stands a better chance. But remember - nagging does not work :)
What about a Linux build?
Since the primary objective of DirectQ is to provide a Direct3D renderer as an alternative, this is out of the question. There are plenty of good Linux clients you can try; check out QuakeOne.com or Inside3D for some ideas.
Will my hardware be able to run DirectQ?