The new website Get Firebug gives you a glimpse of what is coming shortly:

• Inspect and edit HTML
• Tweak CSS to perfection
• Visualize CSS metrics
• Monitor network activity
• Debug and profile JavaScript
• Quickly find errors
• Explode the DOM
• Execute JavaScript on the fly
• Logging for JavaScript

Limitations

* As described earlier, speed improvements only apply on page load for IE. Further DOM queries will use the original getElementsBySelector function
* the speed of CSS2 queries (attribute selectors) are not improved for IE5/6
* because of the nature of the CSS hack, you can only apply one behavior per element

Conclusion

* DOM queries on Firefox seem pretty quick
* XPath is about 150% faster than DOM queries on a Mozilla platform
* XPath is about 1000% faster than DOM queries on an Opera platform
* the expression hack is about 200-400% faster on an IE platform
* Behaviour leaks like a sieve

Gmail greeted me with this screen for a couple hours today.

Seems now that the day is over things are back to normal and Gmail is happy. Well tomorrow is another day… we’ll see how the big G holds up.

As shown on Mashup Feed the average new mashups per day is up to 2.81. And that is just those added to the database here. This is up from 2.6 or so just about 8 weeks ago.

So looks like it may hit 1000 before the year end.

JSONRequest also has provisions for long lasting server initiated, live push of data. Crockford calls this “Duplex”.

“JSONRequest is designed to support duplex connections. This permits applications in which the server can asynchronously initiate transmissions. This is done by using two simultaneous requests: one to send and the other to receive. By using the timeout parameter, a POST request can be left pending until the server determines that it has timely data to send.

Duplex connections can be used in real time notification applications such as process management and finance. It can also be used in collaborative applications such as instant messaging, instant email, chat, games, presentation, and shared applications. “

Alex Russell calls this same server-push technique Comet. I actually like Comet a bit more than Duplex. Duplex is a bit overloaded with a few other uses in tech. Like the half or full duplex with configuring network cards or terminal echo. Not as if I have a vote(just like AJAX sotra stuck), but let’s hope Comet wins.

It’s a new service, so not too surprised that chat is seeing a few bumps. In fact it’s expected. I remember the first few versions of meebo(a web based chat interface for Yahoo, MSN, AOL, and Jabber), and the problems they ran into. One positive aspect of the chat problems are that gmail is unaffected. Email continues to work and is performing well. They’ve integrated it in such a way that quick contacts can fail or be unavailable (like above) but fail gracefully. Many popular web apps, even recent web 2.0 and AJAX apps don’t seem to be designed this way. They fail and fail completely. Designing AJAX apps that can handle partial failures is hard. Many of these app have deep callback stack to get the JavaScript to perform and work seamlessly. There are parallel asynchronous java script calls that need to be requested and handled in whatever order the server responds. So each piece of functionally needs to be carefully crafted to be independent and self sufficient. You need to think about how your app will act if it fails, or worse partially fails. Can it continue to work if it misses a server response or two? Can it error gracefully and continue to work when only a partial set of server functionality is available? This is especially important for companies building desktop replacement applications in which users will rely on for their day to day or even hour to hour work. So take a note from gmail and talk, build apps that are robust to temporary failures. If partial server functionality is available continue to process work and user interaction on the rest of the app. Gracefully poll the server checking for when the full functionality is returned. The error above recovered on it’s own without a reload or restart of the webapp. Impressive to say the least.

On a side note, Gmail itself has been rock solid for me ever since I started using it in June 2004. The spam filters are pretty good, but not perfect (more on that later), and it’s hard to beat the speed of the interface. It’s not the most feature rich mail or collaboration implementation out there but for a small mail volume it does a good job. Works perfect for my personal mail (40-50/day), but I’d have a hard time using it as my primary webmail client for work(200-300/day). I just get too much mail each day for gmail to be useful. It’s missing a few key features to manage extremely large daily mail volume. Saved searches and IMAP support being the first two that come to mind. I need a way to quick search on the same data multiple times a day. Labels work well to automatically categorize and simulate folders but can’t replace a rich search with the option to save. IMAP is a must have for off-line access. POP just doesn’t cut it when you want the server to be your *master* mail store.

AJAX Amazon Music Search

YubNub Suggest (Dojo)

UPDATE: A couple demo’s of my own:

YubNub Suggest
Dojo Autocomplete

Note:
 - It’s only been tested in Firefox 1.5.01

TODO:
 - Test in other browsers
 - Add descriptions to each command
 - Allow selecting with arrow keys