# Gnus vs Sup

- Gnus: Mail and news reader built into GNU Emacs, with back ends for IMAP, POP3, local mail folders and NNTP.
- Sup: Curses email client in Ruby built around threads, labels and fast full-text search over local mail.

## Differences

- Gnus is a mail client that runs inside Emacs; Sup is a full-screen terminal client.
- Only Gnus has built-in IMAP, POP3 and SMTP.
- On Windows, Gnus runs natively and Sup runs through WSL.
- On BSD, Gnus runs natively and Sup builds from source.
- On Android, Gnus runs through Termux and Sup is not available.
- Gnus has mouse support; Sup does not.
- Gnus has calendar support; Sup does not.
- Gnus has S/MIME; Sup does not.
- Gnus has OAuth2 sign-in; Sup does not.
- Sup has Vim-style keys; Gnus does not.
- Gnus is written in Emacs Lisp; Sup in Ruby.
- Configuration: Gnus uses Emacs Lisp in init.el or ~/.gnus.el, and Sup uses ~/.sup/config.yaml and ~/.sup/sources.yaml, plus Ruby hooks.

## Side by side

| | Gnus | Sup |
| --- | --- | --- |
| Interface | Runs inside Emacs | Full-screen terminal interface |
| Language | Emacs Lisp | Ruby |
| License | GPL 3.0 or later | GPL 2.0 or later |
| Linux | Native | Native |
| macOS | Native | Native |
| Windows | Native | Through WSL |
| BSD | Native | Build from source |
| Android | Through Termux | Not supported |
| IMAP | Yes | No |
| POP3 | Yes | No |
| SMTP | Yes | Through a separate tool |
| JMAP | No | No |
| Maildir | Yes | Yes |
| mbox | Yes | Yes |
| notmuch | Through a separate tool | No |
| OpenPGP | Yes | Yes |
| S/MIME | Yes | No |
| OAuth2 sign-in | via plugin | No |
| Threads | Yes | Yes |
| Search | gnus-search: IMAP SEARCH, or notmuch, mu, mairix and other local indexers | Xapian full-text index with a query language |
| HTML mail | built-in, rendered with the Emacs shr library | via the mime-decode hook and an external viewer such as w3m |
| Mouse | Yes | No |
| Multiple accounts | Yes | Yes |
| Offline use | via the Gnus agent or local Maildir back ends | reads local Maildir or mbox; sync with isync or OfflineIMAP |
| Calendar | replies to invitations with gnus-icalendar | No |
| Contacts | via BBDB or EUDC | tracks recent contacts automatically |
| Vim-style keys | No | Yes |
| Configuration | Emacs Lisp in init.el or ~/.gnus.el | ~/.sup/config.yaml and ~/.sup/sources.yaml, plus Ruby hooks |

Pages: [Gnus](https://terminalemail.com/clients/gnus/index.md), [Sup](https://terminalemail.com/clients/sup/index.md)