Microsoft Active Directory vs OpenCA PKI

Microsoft Active Directory has no write-up on Specifiction yet; its figures are above.

OpenCA PKI is free, open-source software for establishing and managing a public key infrastructure, with an out-of-the-box Certification Authority. It is intended for on-premises deployment and is listed for Linux, macOS, self-hosted, and web environments. The project says it implements commonly used protocols with full-strength cryptography; listed capabilities include SCEP support, HSM integration, and certificate profiles. The download page lists OpenCA PKI (SpecialK) version 1.5.1. Installation requires other software, including OpenLDAP, OpenSSL, Apache, and Apache mod_ssl, and OpenCA Tools version 1.3.0 is listed as a prerequisite to install first. The project dates to 1998 and describes its work as volunteer-driven and managed through collaboration and consensus. Community support is available through mailing lists, forums, and online chat; independent third parties offer paid support. Security concerns can be reported privately by email or publicly through the project issue trackers. The documentation page says downloadable documentation is unavailable and notes that the OpenCA Guide for version 0.9.2 is outdated in some parts.