FamilyTreeDNA (FTDNA)
The Y and mtDNA haplotrees used by Visual DNA are copyright © FTDNA and used with permission. The data and results shown are for personal use only. Haplotree, country of origin, and age estimates are provided by FamilyTreeDNA, based on their BigY and mtFull tests and the world's largest Y and mtDNA databases.
Rob Spencers' SNP Tracker and other tools
Rob Spencer has regarding DNA a compilation of very useful tools for the analysis and graphic presentation of complex datasets.
Carlos Quiles' Ancient DNA Database
Dr. Quiles is a rare synthesizer who brings together ancient languages, archaeology, and DNA, stays current with the literature, and writes frequent, detailed interpretations and original insights about our origins. In addition he curates and provides open access to a fine database of worldwide ancient human DNA samples .
Allen Ancient DNA Resource (AADR)
David Reich's Lab curates and makes available this database of ancient human DNA.
Maciamo Hay's Eupedia
Eupedia has fine summaries of modern haplogroup prevalence by country, haplogroup trees, and interpretations of ancient migrations by specific haplogroup.
Wikipedia
Wikipedia articles and their references are a major source for my estimation of ancient SNP paths. The History tab is a dynamic feed from specific Wikipedia pages that illustrate some the natural and cultural events that have shaped ancient migrations and civilizations.