There are obvious, popular, clients that you can see mentioned everywhere. Here's a short list of projects - in no particular order - that I like for trying to approach the Let's encrypt integration differently.<p>tls_certificate_generation - a Docker project for renewing certificates for domain that are resolved by internal DNS. It launches a temporary AWS/DO VMs. ... the project looks dead (doesn't seem to support RFC8555 / ACMEv2).<p>haproxy-lua-acme - an HAproxy client. When you need to renew a certificate, you send a POST request to your HAproxy ... instead of to the LE API directly.<p>Greenlock - just because the author has built a whole set of tools written in JavaScript for various use cases - see below.<p>freshcerts - a Ruby project (also not supporting ACMEv2) that creates a centralized service allowing lightweight scripts on endpoints. I suspect that it fails with ACMEv2 as it doesn't allow changing the server address.<p>acme-client - the BSD version, well because it is part of the distro.
acmetool - the Go project - because it doesn't have any dependency and works as a server listening on port 402.<p>and the complete list is at: https://keychest.net/stories/acmev2-clients