The text of Hathatattvakaumudi is a vast compendium on hatha system of yoga practice and philosophy critically edited and published for the first time. The text is authored by Sundaradeva. Through this work of the author we come to know that he acquired unstinted mastery over ancient Indian literature on yoga and allied sciences. There are ample number of quotations and citations taken from authoritative scriptures which are presented to substantiate validity and authenticity of every yogic concept and practice. This certainly serves the purpose of propagating the very cause of yoga on the traditional lines. This work of Sundaradeva poses as extensive and impressive as that of an encyclopedia of hatha-yoga.
Almost all the topics of hatha-yoga like asana, pranayama up to nadanusandhana in addition to concept of chhayapurusha, etc. are described in the minutest of details. There are several unique practices such as charana, utkranti pranayama, many varieties of nadishuddhi and the like which are in aid to standard hatha practices which are described for the first time in this text. However, one of the many noteworthy contributions of the author of this book lies in his successful effort in presenting a synthetic view of both principle and practice of two seemingly diverse systems of yoga — Hatha and Patanjala and also various diverse traditions of yoga such as bhakti, laya, nada, sparsha etc. We have not as yet come across such an effort made in any other published yogic literature.