Researchers publish papers about the problems that they manage to solve, but they say much less about the other problems, those that remain open even after a long fight. These problems are sometimes briefly mentioned in papers, others are folklore, and only the most famous end up on Wikipedia. Still, I didn't like it that I did not have a central public list of the open problems I had heard about or struggled with.

So I compiled open problems from my own papers, problems that seemed interesting and were left open by other papers, some of my unanswered questions on CStheory, and other sources.

Here is the list, which I will try to keep up-to-date over time to add new problems and update those on which progress is made. Comments and feedback welcome!