Dev:Open Source Projects

Here is a list of some open source software available for jailbroken devices. See TheiPhoneWiki for a list of open source jailbreaking tools. Please add more projects, especially your own projects!

A note on licenses: If a project does not explicitly have a license that gives you the right to use its code, that means it is copyrighted by the developer and you can't use its code in your own projects - in other words, you can read it and learn from it, but don't copy and paste it. If you've published a project that does not have a free license, and you'd like people to be able to use your code if they want to, How to choose a license for your own work and Choose A License may be helpful. GitHub has advice on adding a license to your repository.

A note on contributing: If you'd like to contribute improvements to one of these projects (or even just file a bug report), a great first step is to get in contact with the developer and talk to them about it - you can email them, tweet them, find them on IRC, open an issue on the project page, or whatever method of communication you can find. People are usually pretty happy to hear that another developer is interested enough in their project to want to add something to it. If you'd like to contribute code to a project that is on GitHub (like most of these), GitHub's guide to contributing to open source has helpful advice for how to make a pull request (a formal way to propose your changes so they can be easily integrated). And yes, contributing is worth your time.

Tweaks
Also check out TweakWeek for a long list of relatively simple open source tweaks, organized by rpetrich.