You have written that "XRP Ledger, developed by Ripple, is the best and most efficient technology of a distributed database ever created.". But, as far as I know - Ledger, it's a hardware purse of French developers and at the same time, the name of the campaign.
XRP Ledger is the name of the blockchain developed by Ripple.
See this from the Ripple website:
XRP Ledger Overview
The XRP Ledger is a decentralized cryptographic ledger powered by a network of peer-to-peer servers. The XRP Ledger is the home of XRP, a digital asset designed to bridge the many different currencies in use worldwide. Ripple stewards the development of the XRP Ledger, and advances XRP as a key contribution to the Internet of Value: a world in which money moves the way information does today.
https://developers.ripple.com/xrp-ledger-overview.html