I see these in the System/Library/Extensions/ folder and I wonder what these are for?

Can you write extensions and make drivers with these?

Any help is great.

Also what is an .xml file?

If you can point me in the direction on how to use or write and develop these please let me know.

Thanks.

[Marshall]

A .kext file is a kernel extension. They're generally used for device drivers and other things that need to modify the system at the lowest level. They're not the same as classic Mac OS extensions, as many of the things that classic Mac OS extensions did are done differently in Mac OS X.

Since kernel extensions aren't protected by Mac OS X's memory protection, developers are encouraged to stay away from writing them unless they absolutely have to. Even then, Mac OS X can dynamically load them, so chances are you'd rarely have to add anything to Mac OS X's Extensions folder.

An XML file is a file that uses eXtensible Markup Language. It looks a lot like HTML when you first see it, but whereas HTML describes web pages in a specific format, XML can be used to describe any set of data. http://www.XML.com can provide you with some good information on how it works. Apple uses XML extensively throughout Mac OS X to store various settings, mostly in a "Property List" (.plist) format.

Thanks.

So since that extensions folder has what are more or less drivers is it possible to use that type of file to write drivers for things that have been left out or are not supported in OSX.

How are the .xml files called or used that are found in those folders.
I did find the plist in the files.

I think that this can be used to create some cool kernel addons.
Sounds like something that would be neat to learn when the development tools are out.

Thanks for your information.

later.

This information is on Apple's TechPubs page for Mac OS X,

See http://developer.apple.com/techpubs/macosx/macosx.html

Drivers are built using IOKit, which uses CoreFoundation, which uses XML to serialize Property Lists. If you're really curious, all of the source code for IOKit is available at www.publicsource.apple.com in the Darwin area.