The University of the West maintains a DSBC. While the Vimalaprabha is originally in Tibetan, the reconstructed Sanskrit base text (based on the critical edition by Jagannatha Upadhyaya) is available here as a searchable PDF. This is ideal for linguists.
While a complete, public domain English translation of the entire Vimalaprabha is rare, you can find several high-quality scholarly PDFs and excerpts: vimalaprabha pdf
awareness of external world events and its polemical stance. Key Themes Islamic Theology The University of the West maintains a DSBC