They are famous for their publication of upniShad-bhAShya, vArttika, stuti, prakaraNa, etc.
They have started to upload their books online for benefit of all. Although, they have just made available lectures(प्रवचन) of their inspiration mahAmaNDaleshvara svAmI maheshAnanda giri ji (महामण्डलेश्वर स्वामी महेशानन्दगिरि जी महाराज) on vedAnta-prakaraNa-s, stutiH, etc.; they have confirmed that they are planning to upload all of their saMskR^ita-only publications, which comprise bhAShya, etc.
They have also uploaded mp3 files of lectures of svAmI jI.
Those who have read his books know that his style of teaching intricate subjects was amazingly simple.
They have a maTha in Mount Abu, Rajasthan. Mount Abu is also known as अर्बुदाचलः in saMskR^ita and has a portion of skanda-purANam(स्कन्दपुराणम्) devoted to it which is known as अर्बुदखण्डः . It mentions greatness of the arbudAchala tIrtha.
The maTha is known as sha~Nkara maTha (शङ्कर मठ). Hence, they have a site with the same name.
Finally, they are upAsaka-s of shrI-daxiNAmUrtti-shiva.
Please, visit the site to get the benefits.