Srushtika Neelakantam: I’d like to thank the Apress team, for their guidance throughout publishing my first book; Ms. Pramila Balan and Ms. Prachi Mehta, for patiently handling all my impatient queries; and all the other people at Apress, secretly and silently involved with this book.

Thanks to Sri Krishnadevaraya Trust, the management of my college; to my principal, Dr. M.S. Indira, for always supporting me; to my professors and mentors at my university, Mr. Dilip. K. Sen and Dr. VijayaKarthik, who’ve always steered me in the right direction and provided me with the right resources to achieve what I wanted; and to all my teachers throughout my life—I have had so many wonderful things to learn from each one of you!

Thanks to Mr. Kevin Ngo and Mr. Ram Dayal Vaishnav, for introducing me to virtual reality and WebVR—the journey has been amazing ever since, with your guidance. Thanks also to Mr. Shivagangadhar Kolli, for introducing me to Mozilla in my early days of college; to Ms. Havi Hoffman, for introducing me to MozTechSpeakers and giving me the opportunity to learn new technologies; to my mentor at Mozilla, Ms. Konstantina Papadea, for helping me with every possible thing and providing me with the right resources I needed to complete this book; and to my longtime friends, B.S Archana, Athira Girish, Vineel Reddy, Galaxy Kadiyala, Harsha Vardhan, Santosh Vishwanatham, Akshay Tiwari, Sumanth Damarla, and all my well-wishers, for always inspiring me and supporting me in all my endeavors.

Thanks to my extended family, which consists of so many amazing people who are always ready to share useful things and opportunities with me - you know who you are! To my father, Mr. Manmohan Raju, for always supporting me in all my endeavors; to my mother, Mrs. Vani Priya, for always nagging me to do the right thing; and to my amazing little brother, Mr. Srujan Raj, for always inspiring me to learn new things.

Tanay Pant: I would like to express my warmest gratitude to the many people who saw me through this book and to all those who provided support, read, wrote, assisted, and offered their insights. I would like to thank my family for their huge support and encouragement. Thank you to my father, who always inspired me to do something different, something good, with my life. I could not have asked for a better role model in my life! I am grateful to my mother, who has been the biggest source of positivity and a pillar of support throughout my life.

I would like to thank Donovan Kraeker ( drawvr.com ) for his code contributions in Chapter 6 . I want to thank Apress for enabling me to publish this book and the Apress team for providing smooth passage throughout the publishing process! I also would like to thank the professors at the College of Technology – Pantnagar, who provided me with the support I needed to write this book.

Thank you to Dr. H. L. Mandoria, Dr. Ratnesh Prasad Srivastava, Er. Sanjay Joshi, Er. Rajesh Shyam Singh, Er. B.K. Pandey, Er. Ashok Kumar, Er. Shikha Goswami, Er. Govind Verma, and Er. Subodh Prasad, for your motivation. My deepest gratitude to all the teachers who taught me from kindergarten through engineering. Last but not the least, my thanks and appreciation go to all my friends and well-wishers, without whom this book would not have been possible.

Thank you!