Cydia Installer
Download Cydia Installer for iPhone, iPad or iPod
Cydia is the third party application for Apple iPhone, iPad , iPod and Apple TV. Cydia is not available in Itunes. Apple doesn't allow to install any third party application for their devices. Cydia is the most popular 3rd party apliaction for Apple devices. Therefore you must use an installer to install cydia to your device. You have to provide your device model and firmware version to this installer.Then it downloads the most compatible app to jailbreak your device with fully installation guide .This is not a fully automated software

Install Cydia without jailbreak??

This is really impossible. If you wish to use Cydia you must jailbreak your device. Because apple doesn't allow to install any third party application for the iOS.
Cydia installer is the jailbreaking solution for iPhone, iPad ,iPod and Apple TV.
This software downloads the most compatible jailbreaking exe according to your apple device model.

Currently latest iOS versions are iOS 6.1.3 and iOS 6.1.4. iOS 6.1.4 is only for the iPhone 5.
But Cydia doesn't compatible with these iOS versions. Therefore, your iOS version should iOS 6.1.2 or below.

If your iOS version is iOS 6.1.3

For old iDevice users (iPhone4, iPhone 3GS ,iPod touch4)
You can downgrade your iOS version using Redsn0w and you can use Cydia Installer to install Cydia

For new iDevice users (iPad 4S,5, iPod 5, iPad 3,4,Mini)
You can't downgrade your iOS 6.1.3. You have to wait some tome to install Cydia
Online Cydia installer
Currently there isn't any online Cydia installer available for latest iOS version.
In previously jailbreakMe was the most popular online Cydia installer.  Users could jailbreak their iOS using  one touch.
Cydia Installer still doesn't compatible with Mac and Linux
Mac and linux users please bookmark and check back soon
Download "Cydia Installer" to Windows computer. This is (.rar) file. You have to Winrar to open this file