PLUG Emacs Apps Presentation

This programming language is older than C, but still used by many people today! With it, all kinds of applications can be made that run from within Emacs.

Basic Emacs terminology

buffer: Place in memory where an opened file is stored. These don't necessarily have to have a file associated with them, however. In that case, a buffer would act like a temporary file.
mode: Emacs operates in several "modes", the most prevalent of which is Text mode. Having different modes allows Emacs to colorize files and map keystrokes depending on what kind of file you are editing.
key-binding: The sequence of keys that you have to press in order to perform an action. Emacs can have prefix keys, which means you hit the keys, release them, and then hit something else to complete an action.

The way we refer to key sequences in Emacs is probably a little different than what you're used to. In the previous node, I wrote the keys in a way that looks familiar. Here's what they would look like in the Emacs documentation.

Familiar notation	Emacs notation
Alt+x global-font-lock-mode, ENTER	M-x global-font-lock-mode RET
Control+h, T	C-h T
Control+h, f, what-page, ENTER	C-h f what-page RET
Control+h, i	C-h i

The reason that Alt becomes "M-" is rather esoteric, but has to do with the fact that keyboards used to have a Meta key rather than an Alt key when it was first made. Emacs is old.

Applications

There are 2 kinds of software programs that you can be made for Emacs: helper programs and standalone programs.

Helper programs

Helper programs are Emacs Lisp programs that extend other Emacs modes, but are not considered modes themselves.

auto-fill: Automatically breaks up long lines as you type.
footnote: Allows footnotes to be inserted in a document. It puts a numeric place-holder in the text, like "[1]".
flyspell: Provides as-you-type spell-checking.

These all come with Emacs.

Standalone programs

Standalone programs are those that have their own mode.

The following are available separately.

Program	Description	URL
AUCTeX	Make it easier to write TeX files	http://www.gnu.org/software/auctex/
BBDB	Keep track of people - useful for contact information	http://bbdb.sourceforge.net/
Emacspeak	Audio desktop for the vision-impaired	http://emacspeak.sourceforge.net/
EMMS	Listen to music and manage playlists	http://www.gnu.org/software/emms/
ERC	Modular, extensible IRC Client	http://www.emacswiki.org/cgi-bin/wiki/ERC
Rcirc	"Just works" IRC client	http://www.emacswiki.org/cgi-bin/wiki/rcirc
Jabber	Jabber client	http://intellectronica.net/emacs-jabber/
Gnus	Read email and news, thorough, expert-level	http://www.gnus.org/
MH-E	An easy-to-use, yet featureful, Mail reader	http://mh-e.sourceforge.net/
Muse	Publish documents	http://www.gnu.org/software/emacs-muse/
Planner	Plan your life	http://www.emacswiki.org/cgi-bin/wiki/PlannerMode
w3m	Browse the web	http://emacs-w3m.namazu.org/
Xtla	Revision control helper	http://wiki.gnuarch.org/xtla

The following come with Emacs.

Program	Description
Appt	Get reminders when appointments are near
Calc	Featureful RPN calculator
Calendar	Show the events of the month
Diary	Keep track of appointments
Dired	File manager

Featured software

Gnus

Read email, news, RSS, and anything else you can think of. A bit hard to get working. Features include:

Spam filtering
Sorting email according to rules
Organizing email and news into a Topical view
Scoring articles and hiding uninteresting ones automatically
Can render HTML email
Message threads
Handles a large amount of email and news backends, like IMAP and POP

ERC

Full-featured IRC client. Features include:

Modular design
Autocomplete nicknames and commands
Spell-check messages
Channel-tracking: shows which channels have new messages
Highlight friends and fools
Ignore complete fools
Autojoin channels
Logging
Auto-truncate long channel buffers
Auto-identify to Nickserv
Timestamps
Convert smileys to icons
Translate morse code
Psychoanalyze other channel members
Play chess with other ERC users
Easy to add new custom commands

When combined with Bitlbee (http://www.bitlbee.org/), an AIM, Jabber, MSN, ICQ, and Yahoo to IRC gateway, it can even be used to send messages to buddies from other chat networks.

The #PurdueLUG channel on freenode has a bot called plugbot that runs on a dedicated ERC session, with the help of the ErBot add-on software for ERC (http://www.emacswiki.org/cgi-bin/wiki/ErBot).

Muse

Emacs Muse is an authoring and publishing environment for Emacs. It simplifies the process of writings documents and publishing them to various output formats. Muse uses a very simple Wiki-like format as input.

Muse consists of two main parts: an enhanced text-mode for authoring documents and navigating within Muse projects, and a set of publishing styles for generating different kinds of output.

I maintain it.

A full manual is available in several formats.

PDF: http://www.mwolson.org/static/doc/muse.pdf
HTML (single file): http://www.mwolson.org/static/doc/muse.html
HTML (multiple files): http://www.mwolson.org/static/doc/muse/

Formats:

Blosxom
DocBook
Groff
HTML
Info
LaTeX
PDF
RDF (RSS 1.0)
RSS 2.0
Texinfo
XHTML
XML

Possible uses:

Technical documentation
Web pages (such as this site)
Tutorials
Poems
Compilations
Recipes
Blog entries
Journals
Citations to other sources
Wiki-like knowledge bases
Plan pages (in conjunction with Planner Mode)
Class notes

Features:

Muse is extensible and has a modular codebase.
You can organize your work into projects.
With the optional muse-wiki module, it is easy to make hyperlinks between projects.
Muse works with your favorite helper modes, like outline mode, fill, and flyspell.
Muse can import LaTeX documents with the included muse-convert.el module.

Planner

Planner is a Personal Information Manager (PIM). You can use it to manage your tasks, schedule, and notes.

Manual: http://sacha.free.net.ph/notebook/doc/dev/planner/html/planner-el.html

Core features:

Associate tasks with webpages or files
Take free-form notes that are rendered by Muse

Additional features:

Appt integration (appointment reminder)
Accomplishments for the week
BBDB integration (contacts manager)
Calendar integration
Bookmarks
Cyclic tasks
Deadlines
Diary integration
ERC integration
iCal support
Publish notes to RSS and RDF
Overview of tasks
See how long you spend on tasks

Xtla

Emacs interface to the GNU Arch (http://wiki.gnuarch.org) revision control system.

Interfaces:

Manage "bookmarks" to projects
Associate "partners" with a project
Browse registered archives and projects

The following are available when editing a file that is associated with an Arch project.

See what changed in the project. You can selectively revert unwanted changes.
Make a log message. From there, the changes can be committed.

Q and A

At this time, feel free to ask questions about Emacs or its add-ons. I will demo other Emacs applications on request if I have them.