As it stands, the cloud is not safe for primary storage. I lost some data in the Magnolia bookmarking service fiasco myself, with my most recent backup several weeks before the crash. I only backed up my bookmarks when I remembered to, not having the time to work up an automated downloading script. Now I save all my bookmarks locally, and my twice-weekly backup takes care of everything. My online photo gallery is not in any similar danger, because I wrote it myself with such a failure mode in mind. The photos and tags and descriptions live on my laptop and propagate from there out to my public website. Images and tags that I don't want to be public never even leave my machine.

Why do people use the cloud, then? To put it simply, front-end convenience. I can create a Flickr or Numsum account in minutes, and right away I have a URL I can point my friends to to see what I have created. The cost (lost data) only comes much later. These hosted applications also present a reduced computer security risk to users, compared to desktop-based publishing software such as my photo gallery uses. If you want to use my application, you have to trust my code and run it on your own machine. However, Flickr only runs Javascript on your machine, safely sandboxed in your browser.

I want all of our current hosted-publishing systems move to the desktop. Clearly, a competitive answer to the cloud/hosted systems of today must compete on both convenience and easy security. Using an application must be as easy as surfing the web, and publishing photos, text, and video must only take a few clicks of the mouse.

What I envision is a desktop platform that allows users to download from the web and run (in a sandbox) any compatible software in a single click, where each application is given fine-grained permission to talk with other applications, read and write user data, and publish to the web, and a peer-to-peer communication system for non-public publishing (e.g. LiveJournal-like friend-locked blogging.) Since most users will not have always-on desktops, communications and storage would be optionally mediated by paid and freemium hosted services serving only as relays for encrypted user data.

With this imagined software, a user would be able to get started with photo publishing by finding a good-looking gallery application's website, clicking a special URL, and approving installation. Perhaps the user would then approve the application's request for 1) read-only access to a specified photo directory and 2) publishing permissions (to the public web, approved peers' inboxes, and relay servers). The application might provide a tagging and organization interface itself, or possibly just scrape data out of KPhotoAlbum, FSpot, and Picasa's databases. The user would connect certain tags to defined groups in their master contact list, allowing e.g. grandparents to be shown different sets of photos than coworkers.

Now imagine that at platform installation time, users are provided with a brand-new set of encryption keys and instructed how to hold key-signing parties, assisted by the platform's authentication module. Privacy-sensitive content (photos, blog entries, video, source code) would be created on the desktop, encrypted to group and personal public keys, distributed on personal and paid servers or via P2P, and downloaded to peer machines. At no point would the prime copy of a user's creations be offsite -- and at no time would personal information be out of the control of the user or those they trust with it.

This project is totally feasible in technical and social terms. It could revolutionize user privacy and even be the required bootstrap for layman's practical encrypted communication. It just needs the right group of people to start the work. Comment if you think you could be one of those people.

On local installs of Firefox (or in Windows), Firefox handles its own upgrades, and has the ability to warn the user if any extensions will be disabled due to incompatibility with the new Firefox version. However, when Firefox is managed by an external agent such as APT, no such warning can take place. (There's another problem here—upgrading Firefox when it is running results in gradual bitrot of the running process as it loads mismatched bits of itself from disk.)

This is totally a solvable problem. Deb packages can contain pre-install scripts that check for bad install or upgrade conditions, and I would bet they can also prompt the user for input in questionable circumstances, such as forced disabling of extensions. There's the minor issue of how to handle multiple user accounts, networked /home, etc., but these all seem solvable with a reasonable amount of effort.

I suspect this post will be too late to influence the Firefox 4 release, but I'm filing an enhancement request anyway. Hopefully the developers of other apps with package managers will take this advice as well.

NB: Emacs is not one thing. This post is abut GNU Emacs 23.

Most interaction with Emacs (besides normal typing of text) is via the issuance of commands. These commands almost exclusively involve modifiers like Control and Meta, which correspond to Ctrl and Alt on most keyboards. If you see the keyboard shortcut M-x, you should type the [X] key while holding down [Alt]. Similarly, C-h means [Control]-[h]. Some commands involve a sequence of keystrokes. You can remap all of these later if you wish. (You should also familiarize yourself with some other key and character conventions.)

Here are your first commands: C-g will cancel just about anything (a command in progress, a selection, etc.) and C-x C-c will quit the program. Note that C-x in most programs is "Cut to clipboard"—this is not what it is bound to in Emacs. In fact, none of the usual keyboard shortcuts apply. You'll learn about their replacements soon.

When you first launch Emacs, you will probably see a single window split into two panes, one above the other. (Emacs calls this a vertical split instead of a horizontal split, confusingly, but we'll stick with the convention.) These panes are called windows in the rest of this document. You have a cursor in each one, but only one will be blinking and active. This is the current window. Want to get rid of all windows except the current one? Use C-x 1 to do that. C-x 0 will close the current window.

The stuff you see inside each window is a buffer, which can be anything from a command line to a document to an interactive settings file. You can have a bunch of buffers open at any given time, and each window can be targeted to show any one of them. You will usually just have one window open and keep switching which buffer is being viewed in it. C-x b will give you an interactive prompt that will let you swap out which buffer you are using, and C-x C-b will give you the full list in the current window until you position your cursor over the one you want and hit [enter].

Emacs is always in one major mode at any given time. Major modes generally change with your programming language, and affect syntax highlighting, autocompletion, compilation, etc. There are also minor modes, which can coexist peacefully. Most notably, modes change what certain commands mean. There's a command to move forward by one word, but the meaning of "word" changes between programming languages. (If you're using an s-expression language, for instance, you'll really want the Paredit mode, which lets you sling parens like a master.)

Undo mistakes with C-/. If it really wasn't a mistake after all, you'll still be able to get it back later by undoing some more!

Now that you know the real basics, you're ready to look at all those other Emacs tutorials! Your next steps:

1. Open and save files
2. Keyboard navigation (and why the arrow keys can be trouble)
3. Undo, and redoing by undoing
4. Selection
5. Killing and yanking are not just different words for cutting and pasting
6. Understanding, installing, and enabling modes
7. How to use the amazing help system (C-h)

I'll add to and modify this document as my own understanding progresses.

Oh yeah, and here's some common stuff that isn't mentioned in regular guides:

• Trying to save to a new filename that has a space in it, and Emacs isn't letting you? C-q space will put in a literal space.
• Want to put a newline character in a search or replace pattern? C-q C-j inserts a ^J (line-feed character), which is usually what you want. In DOS mode you'll need to insert an ^M (carriage return) before the line feed, otherwise some programs might freak out.

(defn magic []
  (println "magic happens") ; one too few closing parens

(defn selfr [i]
  (if (< i 0)
    0
    [(selfr (dec i))
     (selfr (dec i))]))) ; one too many closing parens

(defn selfr-caller []
  (selfr 3))

(defn -main [& args]
;  (magic) ; uncomment to make everything work
  (println (selfr-caller)))

If you stare at the code for a bit, you'll see that selfr is defined inside the magic function. So why doesn't the compiler complain that selfr-caller can't see it? What I didn't realize until today (with the help of some wonderful people on IRC) was that defn hoists the declaration to the top-level, where everything can see it... but the assignment won't occur until the code block is actually run.

This kind of bug is extraordinarily tricky to find, since it is ultimately a syntax error but may not show symptoms depending on the execution order of the code. I suppose this could have been prevented by having a better editor, such as one with draconian indentation support (e.g. Emacs) or perhaps a matching-paren highlighting feature.

Now it saddens me to report that JanRain's MyOpenID is effectively dead, as far as anyone can tell. For over a year, there has been a serious malfunction with the client certificate feature, and no indication from JanRain that they are even aware of the problem. I have tried to contact them via multiple email addresses (all of which bounced my message) and via their contact forms. On both their official UserVoice thread and a GetSatisfaction thread, many users report the same issue, but no JanRain representatives weigh in.

For a replacement service, I recommend switching to Clavid. And remember, delegation is your friend.