JSEcoin is a browser-mined cryptocurrency that allows websites to monetize through opt-in mining by visitors. It aims to address issues with traditional cryptocurrencies like power consumption and scaling limitations by mining in web browsers using surplus resources. JSEcoin targets the large market of webmasters and publishers by allowing them to generate revenue through visitor mining without intrusive ads. It has grown an active user base of over 63,000 registered users and 8.5 million opt-in miners since launching in 2018.