Open knowledge technologies are in many ways the backbone of the Internet, providing reliable information and tools for millions of people every day, often without their awareness. Yet across sites of open knowledge technologies, gender gaps persist and exceed the rates of gender inequality in more closed systems of knowledge production. I deem this pattern the irony of openness. To connect across a range of endeavors I construct a definition of openness applicable to a range of products and participation types. Using a framework of self-governance, I identify the complex set of traits and practices that produce openness and in turn determine the quality of our informational tools and content. Using digital trace data from the processes of knowledge production across three case studies –Wikipedia, Open Source Software, and the Open Science Movement – I both identify repeating forms of gender inequality and evaluate activists attempts to intervene and produce more equitable knowledge. My results indicate both profound gender gaps and document the difficult work of creating change in the governance of open knowledge technologies.