PKI.js is described as 'PKIjs is a pure JavaScript library implementing the formats that are used in PKI applications (signing, encryption, certificate requests, OCSP and TSP requests/responses). It is built on WebCrypto (Web Cryptography API) and requires no plug-ins' and is an app in the development category. There are more than 50 alternatives to PKI.js for a variety of platforms, including Windows, Linux, Mac, Web-based and Self-Hosted apps. The best PKI.js alternative is jQuery, which is both free and Open Source. Other great apps like PKI.js are xca - X Certificate and Key management, DHTMLX, Verisign and Zepto.js.