Ajax Girl

OpenKM is a multi-platform application for document management based on GWT, JBoss, and Jackrabbit (the content repository API).

Version 2.0 has been released, which you can test drive to see the application-style interface. The new features in 2.0 include: the previsualization of multimedia elements as images and videos, an improved an rewritten administration interface, a centralized management of templates, an exclusive area to allow users to store their private documentation, a tool for massive import and output data from ZIP files, searches by date ranks as well as translations to more languages.

However, one of the more relevant functions to mention is the indexing of the most common types of files: text, Office, Office 2007, OpenOffice, PDF, HTML, XML, MP3, JPEG, etc.

Source: Ajaxian
Original Article: http://feeds.feedburner.com/~r/ajaxian/~3/288781416/openkm-open-source-document-management

Are child selectors slower than more simple brethren? This is a question that Jon Sykes sought out data for after he read the work of Jim Barraud.

His conclusion?

The skinny is that child selectors are a major performance issue.

This seemed to make sense, but to me I needed some sort of proof rather than just being told it’s that way by someone, so over the last two days I’ve tried two approaches to see if I can replicate the issue.

The first one was rather a half-assed idea that afterwards seems fundamentally flawed as a benchmark.

So I took a new approach which does seem to return some valid and rather interesting findings, particularly regarding Safari and Firefox 3 and how they react to child selectors and performance.

The tests show that there is slow down using child selectors over direct class name declarations in IE6, IE7 and Safari 3. Safari 3 being the most impacted by child selectors. Firefox 2 has some impact, and Firefox 3 doesn’t seem to be impacted at all.

That said, this is a very extreme test, it is not often you’d have 20,000 class definitions in a single page or that all of them would use 4 levels of child selector.

Source: Ajaxian
Original Article: http://feeds.feedburner.com/~r/ajaxian/~3/288766074/css-child-selector-performance

Piotr Dachtera took his 64pola.pl, and created a scalable version using Comet. Dylan reports it as “a Jetty-powered Comet app that uses dojox.cometd on the client-side. It’s a solid implementation that shows chess moves in real-time, and to date is the best all-around Comet game I’ve seen that is live to the world.”

Mathieu Nouzareth then commented that Cafe.com, a Flash based gaming platform also uses Jetty and Comet techniques (compared to AMF etc).

Source: Ajaxian
Original Article: http://feeds.feedburner.com/~r/ajaxian/~3/288734261/live-chess-with-comet

Tom Trenka has detailed a great analysis of JavaScript performance across the various browsers. This is important work, and it reminded me of the JVM days where people tried to use pools and such… to find out that they were bad for performance as newer VM technology came out. When you try to be too tricky you can end up in a bad state as new versions try to optimize the common task, and not your trick.

Eugene Lazutkin had a great explanation on Strings in languages:

Many modern languages (especially functional languages) employ “the immutable object” paradigm, which solves a lot of problems including the memory conservation, the cache localization, addressing concurrency concerns, and so on. The idea is simple: if object is immutable, it can be represented by a reference (a pointer, a handle), and passing a reference is the same as passing an object by value — if object is immutable, its value cannot be changed => a pointer pointing to this object can be dereferenced producing the same original value. It means we can replicate pointers without replicating objects. And all of them would point to the same object. What do we do when we need to change the object? One popular solution is to use Copy-on-write (COW). Under COW principle we have a pointer to the object (a reference, a handle), we clone the object it points to, we change the value of the pointer so now it points to the cloned object, and proceed with our mutating algorithm. All other references are still the same.

JavaScript performs all of “the immutable object” things for strings, but it doesn’t do COW on strings because it uses even simpler trick: there is no way to modify a string. All strings are immutable by virtue of the language specification and the standard library it comes with. For example: str.replace(”a”, “b”) doesn’t modify str at all, it returns a new string with the replacement executed. Or not. If the pattern was not found I suspect it’ll return a pointer to the original string. Every “mutating” operation for strings actually returns a new object leaving the original string unchanged: replace, concat, slice, substr, split, and even exotic anchor, big, bold, and so on.

Tom then went on to detail the rounds that he went through:

• Round 1: Measuring Native Operations.
• Round 2: Comparing types of buffering techniques.
• Round 3: Applying Results to dojox.string.Builder.

There are a few surprises here, and Tom later concludes:

• Native string operations in all browsers have been optimized to the point where borrowing techniques from other languages (such as passing around a single buffer for use by many methods) is for the most part unneeded.
• Array.join still seems to be the fastest method with Internet Explorer; either += or String.prototype.concat.apply(””, arguments) work best for all other browsers.
• Firefox has definite issues with accessing argument members via dynamic/variables

Erik Arvidsson reminds us of the reason to use push(): IE6 and it’s really bad GC.

I look forward to the IE 8 / FF 3 results too.

Source: Ajaxian
Original Article: http://feeds.feedburner.com/~r/ajaxian/~3/288695686/everything-you-wanted-to-know-about-string-performance

This is a follow up to our post last month that listed some of the top tech bloggers according to TechMeme. The goal was to be able to take a look at the individual bloggers who were writing headlines, not just the blogs they wrote for.

As promised, the team (Mark McGranaghan and Henry Work) has put together much more detailed statistics on the blogs and bloggers that publish tech news headlines and has published it over at CrunchBase.

The top 100 blogs are listed here along with the top three authors by publication. The default view is “all time,” which is back to March 2006, but can be toggled to the last 90 days, last month, or last seven days. The image below shows the top ten publications by all time.

The data can also be viewed by author here with the same time toggles.

Blogs and authors can be clicked on to see links back to TechMeme for each of the headlines. Here’s Erick Schonfeld, for example.

This data goes back much further than the TechMeme Leaderboard, and it also calculates things differently. The leaderboard looks at the last 30 days and calculates top sites based on share of headline space, meaning how long a headline stays up affects rankings. Our calculations look only at the raw number of headlines, nothing more.

More data is coming soon. And check out StatBot, a new site that is also doing some great work slicing up data from TechMeme and other sites.

Crunch Network: CrunchBoard because it’s time for you to find a new Job2.0

Source: TechCrunch
Original Article: http://feeds.feedburner.com/~r/Techcrunch/~3/288554288/

PMOG, a multiplayer online game (MOG) that lets users accumulate points while passively surfing the web and then use those points to help or hurt their fellow players, launched out of private beta this morning. We first covered PMOG back in February.

To play PMOG you need to install a Firefox add-on that lets you interact with other users asynchronously on websites you visit. You spend points accumulated by surfing the web on things like mines, which you leave on websites and explode when the next player visits the site. Points are deducted for tripping a mine unless the player has spent points on armor. Other users can also attach “St Nicks” to users who leave a lot of mines, which causes their next mine not to work.

I spent most of my time and points leaving mines all over the web, and then suggesting that founder Justin Hall to go to those sites. For some reason I never got tired of this. But other players create various missions that direct users, in a StumbleUpon fashion, to topic-specific sites.

PMOG has about 15,000 users and the company that created it, GameLayers, says they are ready to open up to everyone that wants to play. The video below give a short tour of the service. More information on their CrunchBase profile.

Crunch Network: MobileCrunch Mobile Gadgets and Applications, Delivered Daily.

Source: TechCrunch
Original Article: http://feeds.feedburner.com/~r/Techcrunch/~3/288577177/

New Indie film site The Auteurs, which is in private beta, is trying to make a big splash around the Cannes Film Festival later this week with a competition. And they’ve lined up some big sponsors to help them.

The competition is sponsored by HP, Facebook and Flip. Users pick up one of 250 free Flip cameras at the festival and shoot a three minute short film. The winner, as judged by a jury, gets a $10,000 cash prize (funded by Facebook) and a HP Workstation with a 30-inch monitor. Everyone gets to keep those Flip cameras, too, which you can sell on eBay for $20 or more.

These movies are going to be awful. The Flip video camera is dead simple to use (unless you are on a Mac, and then it’s exactly the opposite of dead simple to use), but the quality of the video is about as bad as you can get. Given that, I think they should give out awards for the worst movies as well. In fact, I think they should drop the jury idea and post all the videos online and let users vote. That would make for great content.

Anyway, even though the site is invite only at this point, you can get in through a back door - their Facebook application. Just add the application and you’ll have an account on the main site, too.

Putting the competition stunt aside, The Auteurs does have some good indie films on the site already. There is a lot of competition in this space (Jaman, Netflix, others), though. Indie films are in high demand.

Crunch Network: CrunchGear drool over the sexiest new gadgets and hardware.

Source: TechCrunch
Original Article: http://feeds.feedburner.com/~r/Techcrunch/~3/288530849/

I’m going to assume that the fact that some Yahoo search results that point to Google with a malware warning are a sign that their new partnership with McAfee just needs a little tuning. The alternatives are either (1) Google is serving Malware, or (2) Yahoo or McAfee are playing a little joke.

Most results that point to Google don’t have this “feature,” and given the recent love fest between the two companies, the joke angle is probably out. Keep an eye out on this query though. I wouldn’t be surprised to see flags popping up all over the place on that page.

Crunch Network: CrunchBoard because it’s time for you to find a new Job2.0

Source: TechCrunch
Original Article: http://feeds.feedburner.com/~r/Techcrunch/~3/288497349/