Let's Encrypt 宣佈脫離 beta，正式開放：「Leaving Beta, New Sponsors」。
翻資料的時候發現在今年 3/26 的時候，限制已經放寬了：「Rate Limits for Let’s Encrypt」。
首先一張證書只能包括 100 個 hostname，跟原來相同：
Names/Certificate is the limit on how many domain names you can include in a single certificate. This is currently limited to 100 names, or websites, per certificate issued.
再來是每個禮拜可以申請的數量從 5 個 hostname 變成 20 個，另外本來 renew 也算 quota，現在變成不會吃到 quota：
Certificates/Domain limits how many certificates can be issued that contain a single registered domain*.
This is limited to 20 certificates per domain per week. Exception: When you request a certificate with the same exact set of FQDNs as previously-issued certificate, this rate limit does not apply, but the one below does.