Many of us use Collabedit frequently to conduct technical interviews. It is a easy to use online code editor where code can be shared between interviewer & interviewee. It supports most of the common programming languages available like Java, C++, Python, PHP or JavaScript. But recently I have seen Collabedit having server problems frequently. Sometimes the website keeps loading & gets timed out.
So as an alternative I have been using codeshare.io for collaborating & sharing code. It has a free version & works well. And their server didn’t give me any problem till now. So if you are looking for a free Collabedit alternative, you can give codeshare.io a try.