An extensible, customizable, free/libre text editor — and more.
At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing.
The features of GNU Emacs include
Content-aware editing modes, including syntax coloring, for many file types.
Complete built-in documentation, including a tutorial for new users.
Full Unicode support for nearly all human scripts.
Highly customizable, using Emacs Lisp code or a graphical interface.
An entire ecosystem of functionality beyond text editing, including a project planner, mail and news reader, debugger interface, calendar, and more.
A packaging system for downloading and installing extensions.
is an easy-to-use automatic client that fetches and deploys SSL/TLS certificates for your webserver. Certbot was developed by EFF and others as a client for Let’s Encrypt and was previously known as “the official Let’s Encrypt client” or “the Let’s Encrypt Python client.” Certbot will also work with any other CAs that support the ACME protocol.
While there are many other clients that implement the ACME protocol to fetch certificates, Certbot is the most extensive client and can automatically configure your webserver to start serving over HTTPS immediately. For Apache, it can also optionally automate security tasks such as tuning ciphersuites and enabling important security features such as HTTP → HTTPS redirects, OCSP stapling, HSTS, and upgrade-insecure-requests.
Certbot is part of EFF’s larger effort to encrypt the entire Internet. Websites need to use HTTPS to secure the web. Along with HTTPS Everywhere, Certbot aims to build a network that is more structurally private, safe, and protected against censorship.