One of the most urgent debates of our time is about the exact role that new technologies can and should play in our societies and particularly in our public decision-making processes. This paper is a first attempt to introduce the idea of CrowdLaw, defined as online public participation leveraging new technologies to tap into diverse sources of information, judgments and expertise at each stage of the law and policymaking cycle to improve the quality as well as the legitimacy of the resulting laws and policies. First, we explain why CrowdLaw differs from many previous forms of political participation. Second,we reproduce and explain the CrowdLaw Manifesto that the rising CrowdLaw community has elaborated to foster such approaches around the world. Lastly, we introduce some preliminary considerations on the notions of justice, legitimacy and quality of lawmaking and public decision-making, which are central to the idea of CrowdLaw.