Scientific workflows are gaining popularity, and repositories of workflows are starting to emerge. In this paper we de- scribe TopicsExplorer, a data exploration approach for my- Experiment.org, a collaborative platform for the exchange of scientific workflows and experimental plans. Our approach uses a variant of topic modeling with tags as features, and generates a browsable view of the repository. TopicsExplorer has been fully integrated into the open-source platform of myExperiment.org, and is available to users at www.myexperiment. org/topics. We also present our recently developed personalization component that customizes topics based on user feedback. Finally, we discuss our on- going performance optimization efforts that make computing and managing personalized topic views of the myExperiment. org repository feasible.