Thunderbird is the free and open source email client by Mozilla Foundation. I have been using it for some years now. Till now the Thunderbird users had to use an extension Enigmail to use GnuPG. Thunderbird 78 now uses a different implementation of OpenPGP called RNP.

Since RNP library still does not support the use of secret key on smartcards, to use Yubikey or any other GnuPG enabled smartcards, we need manually configure Thunderbird with GnuPG. The steps as said are the following :

Password management should be simple and follow Unix philosophy. With pass, each password lives inside of a gpg encrypted file whose filename is the title of the website or resource that requires the password. These encrypted files may be organized into meaningful folder hierarchies, copied from computer to computer, and, in general, manipulated using standard command line file management utilities.

pass makes managing these individual password files extremely easy. All passwords live in ~/.password-store, and pass provides some nice commands for adding, editing, generating, and retrieving passwords. It is a very short and simple shell script. It's capable of temporarily putting passwords on your clipboard and tracking password changes using git.

You can edit the password store using ordinary unix shell commands alongside the pass command. There are no funky file formats or new paradigms to learn. There is bash completion so that you can simply hit tab to fill in names and commands, as well as completion for zsh and fish available in the completion folder. The very active community has produced many impressive clients and GUIs for other platforms as well as extensions for pass itself.

The pass command is extensively documented in its man page.

Debugging a problem over email/irc/BTS is slow, tedious, and hard. The developer needs to see the your problem to understand it. Debug-me aims to make debugging fast, fun, and easy, by letting the developer access your computer remotely, so they can immediately see and interact with the problem. Making your problem their problem gets it fixed fast.

Ein Ansatz, den Schlüsselaustausch im PGP-System sicherer und für den Benutzer einfacher zu gestalten, ist der OPENPGPKEY-Draft der IETF. Mit der dort beschriebenen Methode kann der Besitzer einer E-Mailadresse den zur Adresse passenden (öffentlichen) PGP-Schlüssel im DNS veröffentlichen.

Keyringer lets you manage and share secrets using GnuPG and Git with custom commands to encrypt, decrypt, recrypt, create key pairs, etc.

Keybase is a website, but it's also an open source command line program. Let's walk through a terminal example, which illustrates what Keybase does. All of this can be embedded into other software, written by anyone.