Possibly the greatest programming book I've read
on
Programming Erlang
·
· Score: 4, Insightful
This book is written by the language's creator, Joe Armstrong, and provides one of the best introductions to a programming language I've ever seen. The entire approach is nicely bottom up, with the idiosyncrasies of the syntax presented immediately so they are not confusing later. More powerful features are introduced, such as the tools for concurrent and distributed programming, with the book finishing off with the immensely powerful Open Telcom Platform and its associated tools, such as the "one server to rule them all" gen_server implementation and Erlang's distributed database, Mnesia.
All in all this is an excellent book about an excellent language and I would highly recommend it to any programmer, especially those concerned with the multicore future which will increasingly demand concurrent programming languages.
Take, for example, the current huge hype about Ruby on Rails, and how it allows the creation of a CRUD web-database application x-times more quickly than every other environment.
Sadly, this is the hype about Rails, a feature called "scaffolding" which lets you build a CRUD web-database application by writing a single line of code. This is pretty much the first feature anyone who touches Rails learns about, and sadly, it appears to be the only feature of Rails the author of the question has been exposed to. Scaffolding is, perhaps, the least interesting feature of Rails.
I've been developing a fairly high profile web site in Rails for the past year (ClickCaster.com). In the past I've used a number of different web development languages and frameworks, particularly PHP and JSP. Rails has not only resulted in the fastest development of any framework I've used, but also the tersest code to implement given functionality.
The real advantage of Rails comes from two different aspects: leveraging Agile development techniques, and exposing a highly cohesive, high-level interface for developing database-backed web pages.
The former, particularly the practice of test driven development in which you write tests first and code second ensures you think about what your code is trying to do first and how it should do that second. Pro-actively writing tests ensures that making modifications to your code does not break existing functionality.
The latter, which forces your code into an MVC model where database, mailer, and other underlying components are neatly isolated from the rest of the program logic, and the presentation templates are isolated from code receiving and processing user input, all atop a very high level framework where the majority of development tasks are abstracted ensures you write terse code which is well modularized by function. This has two advantages: it makes code easy to write in the first place, and it makes it easier to maintain. The author of the question seems to imply that Rails satisfies the former condition, but not the latter. This is not the case.
Rails results in less code, and uses test driven development which ensures that your changes do not break existing functionality, and all you need run to ensure this is "rake test". Bottom line: less code is easier to maintain, and tests prevent modifications from breaking existing functionality. Thus any implied criticism against Rails in this article is completely unwarranted and only serves to illustrate the ignorance of the question's author, not any imagined deficiencies in the Rails framework.
Satellite radio is totally pointless. Why do you need realtime delivery of prescheduled content?
Podcasting is the solution: Get the data when you're connected to a nice, high speed land line, store it on the digital media player of your choice in nice high quality formats where you don't have to make compromises due to transmission speed limits, and then listen to your heart's content. Don't like a particular show? Skip it, no waiting for the show you want to come on. It's all the content [i]you[/i] want constantly at your fingertips.
And best of all it doesn't gib when you go into a tunnel...
Podcasting is getting big with sites like ClickCaster, Podnova, and Odeo. I really do think that Podcasting will bring about the death of traditional radio, and hopefully we'll see Vidcasting as a replacement for TV.
New services allow for turnkey Podcasting
on
Podcasting Hacks
·
· Score: 2, Informative
Services like ClickCaster allow you to record Podcasts directly from the Web via a Java applet or upload your own MP3 files directly to their site. The RSS feed is then constructed automatically from metadata you enter along with the recording; sort of like a Blogger or LiveJournal for Podcasting.
Linux has long since cross the threshold where a typical user (an enthusiast perhaps, but not a hacker) can drop a CD into a typical desktop machine and get a working, internet-connected workstation. OpenSolaris isn't even close yet.
There's the BeleniX LiveCD which includes a Gnome desktop. Drop it into a typical desktop machine and get a working, Internet-connected workstation.
What's the point of making something safer if the government tells you that you're not allowed to tell people you did it?
How about a moral obligation to your customers to reward their decades of patronage by... not killing them?
Philip Morris LIES
on
Safe Cigarettes?
·
· Score: 5, Informative
Of course Philip Morris says there's no safe cigarette. They don't want to invest the money to make their cigarettes safer...
Internal memos from Philip Morris from April 1980 indicate that the tobacco companies have been fully aware of radioactivity in cigarettes for over two decades. They also knew of ways of eliminating the radioactivity, but wrote them off as a "valid but expensive point":
That phosphate fertilizer (specifically superphosphate fertilizer) contains natural radioactivity is a well established fact.
Natural uranium accumulates in the phosphate rock and has been shown to substitute for calcium in the rock structure. Uranium and its daughters are thus carried through the mining and manufacturing process and appear in the commercial product. Soils to which these products are applied show an increase in radioactivity over that naturally present and this increase is a function of the rate of application and the number of years that the fertilizers have been used.
M. E. Counts has shown that the specific [radio]activity [...] increases as the particle size of the superphosphate fertilizer decreases. Thus the smaller particles, which would be more likely to be made airborne by normal farming practices, would be expected to settle out on the tobacco leaves during the growing season and/or be more readily taken up by the plant root system.
210Pb and 210Po are present in tobacco and smoke. The Martell "Hot Particle Theory" has been addressed in the past and has apparently lost popularity in the scientific community (lack of recent publicity in this field). For -particles from 210Po to be the cause of lung cancers is unlikely due to the amount of radioactivity of a particular energy necessary for induction Evidence to date, however, does not allow one to state that this is an impossibility. (Ed: and of course, more recent evidence says just the opposite)
The recommendation of using ammonium phosphate instead of calcium phosphate as fertilizer is probably a valid but expensive point. What Martell appears to be suggesting is the purification of phosphate rock to obtain P2O5 or H3PO4 free of calcium (uranium and daughters) and inert materials. Preparation of ammonium phosphate for fertilizer would then yield a product greatly reduced in or free of the natural radioactivity present in the parent phosphate rock.
Furthermore, switching to indirect fire curing would eliminate virtually all of another carcinogen, nitrosamine, from cigarettes. Nitrosamine was previously found in BEER thanks to direct fire curing of barley. Switching to indirect fire curing of barley reduced nitrosamine in beer to indetectable levels. Yet Philip Morris makes Marlboros, cigarettes with more nitrosamine than any others in the world.
Yes, believe what Philip Morris says, because if you realized there could be a safe cigarette, it would cost them a lot of money...
Here's two simple manufacturing changes they could make which would eliminate the two most potent carcinogens from cigarettes. But I guess it's just cheaper for Philip Morris to kill their customers.
Written text has the very interesting property of linearity, which matches it to the linear processing of spoken discourse, for which we have hardwired functions in brain. How could you "improve" on that?
Daniel Dennett, in his book Consciousness Explained, argues that brain processes are inherently parallel, and that the relatively slow speed of speech/linear thinking compared to the rest of the brain's processes is because after birth we develop a sort of serial "virtual machine" by subvocally autostimulating our language processing center with our speech center. He contends that none of this is actually hardwired into the brain but our enormous mental plasticity causes it to inevitably develop when we are exposed to the speech patterns of other humans (although he does suggest genetic fixing of speech traits via the Baldwin Curve)
The actual way our brain stores and processes information is ontological (in the information theory sense), i.e. a graph. So "Xanalogical"/ontological/web-like information structures are actually closer to what our brain operates on than a linear narrative.
...the ultimate Halloween strange brew/jungle juice dispenser:
Get a milk crate and a metal vat/trough/recepticle of some sort to stick inside the milk crate.
Next mount a skull dangling over this vat, attached to the top edge of the milk crate, dangling over the top of the vat.
Install a recirculating pump which pulls liquid out of the vat and shoots it out the skull's mouth, back into the vat.
Fill the vat with jungle juice and dry ice.
You now have the ultimate Halloween drink dispenser. People just hold their cups under the skull's mouth, or otherwise it disappears into the frothy whiteness that forms on top from the dry ice.
Calling the gc method suggests that the Java Virtual Machine expend effort toward recycling unused objects in order to make the memory they currently occupy available for quick reuse.
You really have to love languages where a invocation "suggests" that the method "expend effort"
When control returns from the method call, the Java Virtual Machine has made a best effort to reclaim space from all discarded objects.
Good effort! You did your best, son! Good hussle out there. It's too bad you're still gobbling up 100MB of RAM, but don't worry tiger, we'll get 'em next time.
...because with cassettes the media were physically incompatible. With HD-DVD and Blu-ray it will be possible to make dual format players which can read BD-ROM/HD-DVD/DVD (provided the licensing costs come down and the thing doesn't cost an arm and a leg)
Although I do think Blu-Ray will win out in the end as Sony pushes a large number of Blu-Ray players into production with the PS3, meaning there will be a very large installed base of Blu-Ray players right off the bat. This will also help lower the price point for both the drives and the media as everything is ramped up into volume production.
Dear HBO,
I love your programming. But cable TV is way too expensive? Won't you please offer your shows for download via BitTorrent for $20/mo? I'd pay it. A lot of other people would too, if it meant legal torrents. So why not evolve rather than viciously trying to protect your antequated push model of content distribution?
Auto/hiding task bar [rejected]
CD-ROM Autorun [rejected]
ClearType [rejected]
Excel/Multiplan [rejected]
Hypertext Help [rejected]
Pivot Table [rejected]
VFAT Filing System [rejected]
Word for DOS [rejected]
I must say I am rather shocked by the Science Referees responses to your comment. The first seemed like a relatively balanced technical critique, but the second was a completely non-technical, vitriolic response by someone who writes as if they have a personal vendetta. Ive heard this paper referred to as the smoking gun of anthropogenically forced climate change, and to discover that such a title was awarded to a paper whose criticisms were dismissed without fair review, especially in a publication such as Science, is frankly rather disturbing.
I wish the best of luck to you in getting your voice heard, as it seems nowadays that taking a cautionary approach to climate change is becoming an increasingly unpopular standpoint, and I find it rather sad that legitimate scientific inquiry is being reduced to little more than a popularity contest.
But the most telling of all is that the author of the paper itself wrote in to Dr. Pielke's blog and noted that the second reviewer who you quoted is a total twit: http://climatesci.atmos.colostate.edu/?p=26
The authoritative (sounding) 2nd referee doesnt realize how small the fluctuations of the global mean energy balance with space are, even in the presence of realistic ENSO and large scale ocean dynamics variability, in the absence of external forcings. The measured/inferred imbalance, as a decadal-mean global-mean, is huge. It implies a correspondingly large external forcing that has yet to be responded to. Any doubts about this interpretation should be erased by a few more years of data. Accurate measurements are continuing and the number of profiling floats is increasing. This planetary metric will become more precise and has the potential to become very useful as the record gets longer. However, to be most useful, its significance needs to be widely recognized. Hopefully any doubting oceanographers have an open mind I dont think that we have a decade to convince them.
So the guy you're using to argue that Dr. Pielke, director of the American Association of State Climatologists, is an "idiot", seems to be pretty damn clueless.
But hey, you duped all of/., I'm modded +4 and you're modded +5. Well done! Bullshit plays well here, I guess.
The Java System Messaging Server is a key component of the Java System Communications software portfolio, which also includes the Java System Calendar Server and Java System Instant Messaging plus the Java System Synchronization tool and the Java System Connector for Microsoft Outlook. Integration across these products enables features such as calendar event and task deadline reminders as well as offline forwarding of alerts.
Shares of Apple Computer (AAPL:Nasdaq - commentary - research) set an all-time high on Friday following a disappointing report from Dell (DELL:Nasdaq - commentary - research) and amid rumors about a major new partnership.
According to market chatter, Apple is set to announce a deal with Google (GOOG:Nasdaq - commentary - research) calling for Google to offer Apple's iTunes music store through its own site. The rumored deal would pair the nation's leading online music store with its leading search engine.
There's "speculation of an iTunes launch," says Paul Foster, an options strategist at Theflyonthewall.com. "Google is going to offer iTunes somehow on their platform," according to the rumor, he says.
Apple spokesman Steve Dowling said the company doesn't comment on "rumors and speculation." A Google representative did not immediately respond to requests for comment.
Meanwhile, Apple's shares might well have benefited from Dell's pain. The computer giant missed Wall Street's revenue targets for its just-completed quarter by $300 million and cautioned analysts that they needed to bring down their revenue targets for its current quarter.
Dell's stumble is in contrast to Apple, which has seen its computer sales and share in the PC market surge in recent quarters.
"Some investors seem be rotating out of Dell into Apple," says Foster. "Investors kind of have the attitude that Dell's weakness is Apple's strength."
Shares of Apple closed regular trading up $2.10, or 4.8%, on Friday to $46.10. The company's shares traded up as much as $2.22, or 5%, intraday. Volume totaled nearly 33 million shares, well above its three-month norm of 18.6 million shares.
Multiple vulnerabilities were identified in MIT Kerberos, which could be exploited by remote attackers to execute arbitrary commands or cause a denial of service.
The first issue occurs in the MIT krb5 Key Distribution Center (KDC) implementation when processing specially crafted TCP/UDP requests, which could be exploited by an unauthenticated attacker to cause a denial of service or execute arbitrary code on the KDC host.
The second vulnerability is due to a double-free error in the "krb5_recvauth()" function, which could be exploited by an unauthenticated remote attacker to execute arbitrary code in the context of a program calling the vulnerable function (this includes the kpropd program which typically runs on slave Key Distribution Center hosts).
* Affected Products *
MIT Kerberos 5 version 1.4.1 (krb5-1.4.1) and prior
Wonder how similar it will be to AJAX on Rails, one of the best AJAX abstractions I've seen to date, using the excellent Ruby on Rails object persistence and MVC framework
This book is written by the language's creator, Joe Armstrong, and provides one of the best introductions to a programming language I've ever seen. The entire approach is nicely bottom up, with the idiosyncrasies of the syntax presented immediately so they are not confusing later. More powerful features are introduced, such as the tools for concurrent and distributed programming, with the book finishing off with the immensely powerful Open Telcom Platform and its associated tools, such as the "one server to rule them all" gen_server implementation and Erlang's distributed database, Mnesia.
All in all this is an excellent book about an excellent language and I would highly recommend it to any programmer, especially those concerned with the multicore future which will increasingly demand concurrent programming languages.
Sadly, this is the hype about Rails, a feature called "scaffolding" which lets you build a CRUD web-database application by writing a single line of code. This is pretty much the first feature anyone who touches Rails learns about, and sadly, it appears to be the only feature of Rails the author of the question has been exposed to. Scaffolding is, perhaps, the least interesting feature of Rails.
I've been developing a fairly high profile web site in Rails for the past year (ClickCaster.com). In the past I've used a number of different web development languages and frameworks, particularly PHP and JSP. Rails has not only resulted in the fastest development of any framework I've used, but also the tersest code to implement given functionality.
The real advantage of Rails comes from two different aspects: leveraging Agile development techniques, and exposing a highly cohesive, high-level interface for developing database-backed web pages.
The former, particularly the practice of test driven development in which you write tests first and code second ensures you think about what your code is trying to do first and how it should do that second. Pro-actively writing tests ensures that making modifications to your code does not break existing functionality.
The latter, which forces your code into an MVC model where database, mailer, and other underlying components are neatly isolated from the rest of the program logic, and the presentation templates are isolated from code receiving and processing user input, all atop a very high level framework where the majority of development tasks are abstracted ensures you write terse code which is well modularized by function. This has two advantages: it makes code easy to write in the first place, and it makes it easier to maintain. The author of the question seems to imply that Rails satisfies the former condition, but not the latter. This is not the case.
Rails results in less code, and uses test driven development which ensures that your changes do not break existing functionality, and all you need run to ensure this is "rake test". Bottom line: less code is easier to maintain, and tests prevent modifications from breaking existing functionality. Thus any implied criticism against Rails in this article is completely unwarranted and only serves to illustrate the ignorance of the question's author, not any imagined deficiencies in the Rails framework.
They have the most computing power of anyone on earth. They're trying to sort the world's information. What better to do that with than strong AI?
Podcasting is the solution: Get the data when you're connected to a nice, high speed land line, store it on the digital media player of your choice in nice high quality formats where you don't have to make compromises due to transmission speed limits, and then listen to your heart's content. Don't like a particular show? Skip it, no waiting for the show you want to come on. It's all the content [i]you[/i] want constantly at your fingertips.
And best of all it doesn't gib when you go into a tunnel...
Podcasting is getting big with sites like ClickCaster, Podnova, and Odeo. I really do think that Podcasting will bring about the death of traditional radio, and hopefully we'll see Vidcasting as a replacement for TV.
Services like ClickCaster allow you to record Podcasts directly from the Web via a Java applet or upload your own MP3 files directly to their site. The RSS feed is then constructed automatically from metadata you enter along with the recording; sort of like a Blogger or LiveJournal for Podcasting.
There's the BeleniX LiveCD which includes a Gnome desktop. Drop it into a typical desktop machine and get a working, Internet-connected workstation.
It Pays To Read The Article! Yay!
Internal memos from Philip Morris from April 1980 indicate that the tobacco companies have been fully aware of radioactivity in cigarettes for over two decades. They also knew of ways of eliminating the radioactivity, but wrote them off as a "valid but expensive point":
Furthermore, switching to indirect fire curing would eliminate virtually all of another carcinogen, nitrosamine, from cigarettes. Nitrosamine was previously found in BEER thanks to direct fire curing of barley. Switching to indirect fire curing of barley reduced nitrosamine in beer to indetectable levels. Yet Philip Morris makes Marlboros, cigarettes with more nitrosamine than any others in the world.
Yes, believe what Philip Morris says, because if you realized there could be a safe cigarette, it would cost them a lot of money...
Here's two simple manufacturing changes they could make which would eliminate the two most potent carcinogens from cigarettes. But I guess it's just cheaper for Philip Morris to kill their customers.
Daniel Dennett, in his book Consciousness Explained, argues that brain processes are inherently parallel, and that the relatively slow speed of speech/linear thinking compared to the rest of the brain's processes is because after birth we develop a sort of serial "virtual machine" by subvocally autostimulating our language processing center with our speech center. He contends that none of this is actually hardwired into the brain but our enormous mental plasticity causes it to inevitably develop when we are exposed to the speech patterns of other humans (although he does suggest genetic fixing of speech traits via the Baldwin Curve)
The actual way our brain stores and processes information is ontological (in the information theory sense), i.e. a graph. So "Xanalogical"/ontological/web-like information structures are actually closer to what our brain operates on than a linear narrative.
...the ultimate Halloween strange brew/jungle juice dispenser:
Get a milk crate and a metal vat/trough/recepticle of some sort to stick inside the milk crate.
Next mount a skull dangling over this vat, attached to the top edge of the milk crate, dangling over the top of the vat.
Install a recirculating pump which pulls liquid out of the vat and shoots it out the skull's mouth, back into the vat.
Fill the vat with jungle juice and dry ice.
You now have the ultimate Halloween drink dispenser. People just hold their cups under the skull's mouth, or otherwise it disappears into the frothy whiteness that forms on top from the dry ice.
No, I think it's just indicative that you didn't read the other comments before posting. The timestamp on that +5 comment is nearly an hour before you posted yours.
You really have to love languages where a invocation "suggests" that the method "expend effort"
Good effort! You did your best, son! Good hussle out there. It's too bad you're still gobbling up 100MB of RAM, but don't worry tiger, we'll get 'em next time.
Although I do think Blu-Ray will win out in the end as Sony pushes a large number of Blu-Ray players into production with the PS3, meaning there will be a very large installed base of Blu-Ray players right off the bat. This will also help lower the price point for both the drives and the media as everything is ramped up into volume production.
And let's not forget, 200GB 8-layer discs. Yummy.
Dear HBO, I love your programming. But cable TV is way too expensive? Won't you please offer your shows for download via BitTorrent for $20/mo? I'd pay it. A lot of other people would too, if it meant legal torrents. So why not evolve rather than viciously trying to protect your antequated push model of content distribution?
Here's a list of their rejected submissions:
Auto/hiding task bar [rejected] CD-ROM Autorun [rejected] ClearType [rejected] Excel/Multiplan [rejected] Hypertext Help [rejected] Pivot Table [rejected] VFAT Filing System [rejected] Word for DOS [rejected]
Futurists were wrong in the past, therefore they can never be right, QED.
That's some sound logic...
Bingo. See American Association of State Climatologists President Dr. Roger Pielke Sr's. analysis of the Webster et al. paper, which was largely blown out of proportion by the press as a definitive link between global warming and increased hurricane activity.
I really have to wonder what kind of crazy open source zealot would turn down free beer because the manufacturer won't divulge the recipe...
But the most telling of all is that the author of the paper itself wrote in to Dr. Pielke's blog and noted that the second reviewer who you quoted is a total twit: http://climatesci.atmos.colostate.edu/?p=26
So the guy you're using to argue that Dr. Pielke, director of the American Association of State Climatologists, is an "idiot", seems to be pretty damn clueless.
But hey, you duped all of /., I'm modded +4 and you're modded +5. Well done! Bullshit plays well here, I guess.
Not all scientists agree that anthropogenic climate forcings are the primary cause of global warming. And hey, this guy is director of the American Association of State Climatologists and he's peer reviewed. He also resigned Bush's panel on climate change because no one else wanted to listen to a dissenting opinion, they were too up in arms about global warming alarmism like this dude
http://www.fixedearth.com/electric.html
e x.html
http://www.badastronomy.com/bad/misc/mccanney/ind
Yeah, these people are total crackpots
Just use that in conjunction with the SJS Directory Server's identity synchronization with Windows AD environments and you're money.
http://www.thestreet.com/_googlen/tech/hardware/10 237939.html?cm_ven=GOOGLEN&cm_cat=FREE&cm_ite=NA
Shares of Apple Computer (AAPL:Nasdaq - commentary - research) set an all-time high on Friday following a disappointing report from Dell (DELL:Nasdaq - commentary - research) and amid rumors about a major new partnership.
According to market chatter, Apple is set to announce a deal with Google (GOOG:Nasdaq - commentary - research) calling for Google to offer Apple's iTunes music store through its own site. The rumored deal would pair the nation's leading online music store with its leading search engine.
There's "speculation of an iTunes launch," says Paul Foster, an options strategist at Theflyonthewall.com. "Google is going to offer iTunes somehow on their platform," according to the rumor, he says.
Apple spokesman Steve Dowling said the company doesn't comment on "rumors and speculation." A Google representative did not immediately respond to requests for comment.
Meanwhile, Apple's shares might well have benefited from Dell's pain. The computer giant missed Wall Street's revenue targets for its just-completed quarter by $300 million and cautioned analysts that they needed to bring down their revenue targets for its current quarter.
Dell's stumble is in contrast to Apple, which has seen its computer sales and share in the PC market surge in recent quarters.
"Some investors seem be rotating out of Dell into Apple," says Foster. "Investors kind of have the attitude that Dell's weakness is Apple's strength."
Shares of Apple closed regular trading up $2.10, or 4.8%, on Friday to $46.10. The company's shares traded up as much as $2.22, or 5%, intraday. Volume totaled nearly 33 million shares, well above its three-month norm of 18.6 million shares.
http://www.frsirt.com/english/advisories/2005/1066
:
:a tch_1.4.1.txt a tch_1.4.1.txt
6 - 2005-002-kdc.txt - 2005-003-recvauth.txt
FrSIRT Advisory : FrSIRT/ADV-2005-1066
CVE Reference : CAN-2005-1174 - CAN-2005-1175 - CAN-2005-1689
Rated as : Critical
Remotely Exploitable : Yes
Locally Exploitable : Yes
Release Date : 2005-07-12
* Technical Description *
Multiple vulnerabilities were identified in MIT Kerberos, which could be exploited by remote attackers to execute arbitrary commands or cause a denial of service.
The first issue occurs in the MIT krb5 Key Distribution Center (KDC) implementation when processing specially crafted TCP/UDP requests, which could be exploited by an unauthenticated attacker to cause a denial of service or execute arbitrary code on the KDC host.
The second vulnerability is due to a double-free error in the "krb5_recvauth()" function, which could be exploited by an unauthenticated remote attacker to execute arbitrary code in the context of a program calling the vulnerable function (this includes the kpropd program which typically runs on slave Key Distribution Center hosts).
* Affected Products *
MIT Kerberos 5 version 1.4.1 (krb5-1.4.1) and prior
* Solution *
Upgrade to krb5-1.4.2 release
http://web.mit.edu/kerberos/dist/index.html
Or apply patches
http://web.mit.edu/kerberos/advisories/2005-002-p
http://web.mit.edu/kerberos/advisories/2005-003-p
* References *
http://www.frsirt.com/english/advisories/2005/106
http://web.mit.edu/kerberos/advisories/MITKRB5-SA
http://web.mit.edu/kerberos/advisories/MITKRB5-SA
* Credits *
Vulnerabilities reported by Daniel Wachdorf and Magnus Hagander
Wonder how similar it will be to AJAX on Rails, one of the best AJAX abstractions I've seen to date, using the excellent Ruby on Rails object persistence and MVC framework