iPhone Development

The iPhone is running a streamlined version of Mac OS X. It uses a Mach kernel, BSD Unix, Cocoa frameworks,
Mac OS X application bundles, and other portions of the Mac operating system.

The iPhone has 8192 MB (8 GB) of Flash RAM
installed. OS X and the iPhone default applications take up about 700 MB . The iPhone also has 128 MB of system RAM used by the running applications.

Sitting above the Mach kernel is the BSD layer with the following directory structure:

/bin
    Contains: launchctl, ln, mkdir, mv, rm, cat, expr
/sbin
    Contains: fsck, fsck_hfs, fstyp, fstyp_hfs, mount, mount_hfs, kextload, launchd
/etc
    Contains: bluetool, racoon, fstab, master.passwd, passwd, ttys, ppp, services, group, hosts, networks
/var/log
    contains: flat files
/usr
    /bin
       contains: ditto, sed
    /lib
       contains: libcrypto, libgcc, libobjc, libsqulite, libstdc++, libz
    /local
       contains:
    /sbin
       contains: fdisk
/Applications
       contains:
/Library
       contains:
/System
    /Library
       /CoreServices
          contains: SpringBoard, mDNSResponder
       /Frameworks
          contains: List of iPhone Frameworks:

- AddressBook
- AddressBookUI
- AppSupport
- BluetoothManager
- Calendar
- Camera
- CFNetwork
- Celestial
- CoreAudio
- CoreFoundation
- CoreGraphics
- CoreSurface
- CoreTelephony
- CoreVideo
- DeviceLink
- Foundation
- GraphicsServices
- GMM
- IAP
- IOKit
- IOMobileFramebuffer
- ITSync
- JavaScriptCore
- LayerKit
- MBX2D
- MBXConnect
- MeCCA
- Message
- MessageUI
- MobileBluetooth
- MobileMusicPlayer
- MoviePlayerUI
- MultitouchSupport
- MusicLibrary
- OpenGLES
- PhotoLibrary
- Preferences
- Security
- System
- SystemConfiguration
- TelephonyUI
- UIKit
- URLify
- WebCore
- WebKit