Difference Between Cydia and Installer
Apple’s strict rules and regulations on what can and can’t be sold in the Apple App Store has prodded a lot of developers to seek for other means to market their products to iPhone users without using the Apple App Store. This need spawned the production of Installer.app. This application allows users to download applications to their jailbroken iPhone without going through the Apple App Store and their strict regulations. Cydia was created much later to address some of the shortcomings that Installer had. The biggest difference between the two is that Cydia is still being actively developed while Installer has been dropped by its author to pursue another package management application called Icy, which is compatible with Cydia repositories and can download applications from there.
Installer has been a closed source application from the very beginning up till the end, making its revival quite unlikely. On the other hand, Cydia is an open source application, which is a contributing factor to its longevity. One of the reasons why Installer was discontinued is the way it delivers the application to the phone of the user. Installer used XML files to transport the information, just like in RSS feeds. Cydia utilized the tried and tested package delivery system that is being used in UNIX like operating systems, like Linux, called APT. It is much better as its long track record ensures its stability and it also has the ability to track and download dependencies, allowing for fewer problems that a user might encounter when installing an application with multiple dependencies.
As Installer has been discontinues, developers have stopped deploying their applications on it. A lot of developers have switched to using Cydia as their main method of getting the applications to the user. Almost all applications and repositories are now APT compatible so that they can be downloaded via Cydia. Even Icy, the replacement to Installer fails to match-up to Cydia, prompting the developers to shutdown development and release its code under the MIT license.
Summary:
1. Installer is older compared to Cydia
2. Cydia is still being developed while the development of Installer has been halted
3. Cydia is open source software while Installer is closed source
4. Cydia uses the same methodology as Linux does to transport the applications while Installer uses XML files
5. Cydia repositories are still full of applications while Installer repositories have all dried up