Cydia™ is Debian APT on the iPhone. Think AppStore, but with packages you could never get direct through Apple. Created by Jay Freeman (saurik), Cydia™ is a feature-rich AppStore competitor. Full themes to completely make over your iPhone's & iPod Touch look are available through WinterBoard. Video recording is possible using Cycorder or Video Recorder for 3G. You can share your iPhone's 3G connection with your laptop using PdaNet, or get free music, videos, and torrents using dTunes. Take complete control of your iPhone with SBSettings.
You'll find Cydia™ right there on your iPhone after you jailbreak your iPhone. Using it is easy - browse the categories, check what's new, or peruse the featured section to see the current popular apps. There's hundreds (getting into the thousands) of themes to choose from. Cydia™ is easily searchable via the iPhone - but if you're wanting to browse what's available from your browser.
Section:Development Name: bsdiff Version: 4.3-1 Description: binary is to text, as bsdiff is to diff Dependence:bzip2 Size: 6824 View in:Cydia Download:.deb
Section:Development Name: XML Parser Toolkit Version: 2.0.1-3 Description: stream-oriented XML parser written in C Size: 69300 View in:Cydia Download:.deb
Section:Development Name: GNU Portable Threads Version: 2.0.7-2 Description: portable threading library used by X Size: 47050 View in:Cydia Download:.deb
Section:Development Name: GNU C Compiler Version: 4.2-20080604-1-8 Description: a native c compiler _on_ the phone Dependence:csulibgccodcctools Size: 31519904 View in:Cydia Download:.deb
Section:Development Name: libxml2 Version: 2.6.32-7 Description: very popular XML parser from Gnome Dependence:libxml2-lib Size: 90670 View in:Cydia Download:.deb
Section:Development Name: Darwin CC Tools Version: 286-8 Description: linker and assembler for the iPhone Dependence:openssluuid Size: 1092318 View in:Cydia Download:.deb