Ghilbert is a website for math enthusiasts to collaborate on mathematical proofs. It contains a huge collection of proofs and many tools to help you write proofs. These proofs are much more detailed than anything you would find in a textbook. Each step is spelled out in precise detail and can be directly traced back to a basic axiom or a definition.
Ghilbert is still a work in progress. Important theorems and tools are still missing, but it has huge potential. It's meant to be built up like Wikipedia on a crowd-sourced model. We would love for you to contribute to the website. If you having any questions please don't hesitate to contact us on the the Ghilbert mailing list.
Here are a few links to help get you started: