NNexus: Towards an Automatic Linker for a Massively-Distributed Collaborative Corpus. Collaborative online encyclopedias such as Wikipedia and PlanetMath are becoming increasingly popular. In order to understand an article in a corpus a user must understand the related and underlying concepts through linked articles. In this paper, we introduce NNexus, a generalization of the automatic linking component of PlanetMath.org and the first system that automates the process of linking encyclopedia entries into a semantic network of concepts. We discuss the challenges, present the conceptual models as well as specific mechanisms of NNexus system, and discuss some of our ongoing and completed works