Can I extend ExpressionEngine with Codelgniter?

[eluser]darrenm[/eluser]
I have to disagree with some of that.

It all depends what you want to extend. If you want to extend the behaviour of EE sessions you're not going to get very far.

If however you want to extend the behaviour of the channel entries template tag, then there is a huge amount you can do.

Perhaps the OP could clarify what the end goal is which would help establish if EE is the right tool for the job.