1. A computer-implemented process for extracting topically related keywords from topically related documents, comprising: using a computer to perform the following process actions: accessing a set of topically related documents; identifying a number of candidate keywords from the set of related documents, wherein a candidate keyword can be an individual term or a multiple word phrase; forming a weighted keyword candidate-document matrix using the candidate keywords; partitioning the keyword candidate-document matrix into multiple groups of keyword candidates; identifying dense clusters of keyword candidates in each of the groups of keyword candidates whose density exceeds a prescribed density threshold; and for each of the identified dense clusters, designating the keyword candidates associated with that cluster as topically related keywords.