5 ms·

How domains became backwards

95 points by advisedwang 14y ago

polymathist 14y ago
Interesting. Now I wonder why Java decided to go the other way with a reversed domain name for packages. E.g., com.company-name.package-name
- gabipurcaru 14y ago
  well, for the same reasons the urls _should_ be the other way around, plus avoiding inconsistencies with other languages I guess (don't know what languages supported dot-named packages at that time, but I don't think they were the first ones)
- syncsynchalt 14y ago
  In the initial implementation package names were literally mapped to a path with the equivalent of subst(".", "/"). So in that sense the java package names are based on the hierarchy of a filesystem.
  - greenyoda 14y ago
    Also, the method name goes to the right of the class name, so the only reasonable way to have a hierarchical name that reads in a single direction is to put the most general qualifier on the left and the most specific on the right: com.mydomain.mypackage.MyClass.staticMethod()
opminion 14y ago
Funny to think that if Twitter handles were fragments of email addresses they would be backwards: com.twitter@holysee --- By the way, this must be a mistake: This is a clearly a byproduct of the right-to-left language of the designers of these systems
- DLWormwood 14y ago
  That language is math. Which, due to historical accident, was inspired by Arabic writing, rather than the Latin variety.
  - andrewcooke 14y ago
    that sounds interesting, but i'm having a hard time getting my head round it. can you give an example where math is right to left? [edit oh, numbers! thanks! i was thinking about algebra.]
    - Turing_Machine 14y ago
      Think of the standard addition and multiplication algorithms. You start with the rightmost place, right?
    - Retric 14y ago
      Think about basic math aka addition, subtraction, and multiplication work. 1237 + 4567 7+7 = 14 = 4 3+6 + 1 = 10 = 0 2+5+1 = 7 1+4 = 5 5704 That's right to left. If we wrote numbers left to right we the 1's place would be on the left.
    - lutusp 14y ago
      Sure -- Scheme: Link: http://weber.marblefalls.txed.net/mfhs/academics/electives/compsci/R0SchExprs.htm http://weber.marblefalls.txed.net/mfhs/academics/electives/c... Example: (+ 5 (* 10 x)) Which more or less means 5 + 10 * x in everyday notation. Compare to Reverse Polish Notation (used in Hewlett-Packard calculators and elsewhere), which would express the above as: 10 x * 5 +
    - T-hawk 14y ago
      Numeric notation is built right to left. To count up from 1 to 9 uses single digits, of course. Then to go from 9 to 10, the ones place increments and rolls over, and we add the new tens digit on the left, not the right.
jbert 14y ago
The UK "Grey Book" email system (http://en.wikipedia.org/wiki/Coloured_Book_protocols http://en.wikipedia.org/wiki/Coloured_Book_protocols) used email addresses the other way around (in the same timeframe that the UK was using a stack over X.25 as their internetworking protocol). For example, a user at Imperial College (IC) would have been: user@uk.ac.ic, rather than user@ic.ac.uk as they might today. Email gateways existed to convert between the different systems, but when all country codes were added to the internet, some addresses were simply ambiguous. (An address ending in .cs might be either czechoslavakia or a computer science department.) The main email software responsible for this slicing and dicing was known as PP, which helps explain the excellent quote on ASR (alt.sysadmin.recovery) a few years later: http://home.xnet.com/~raven/Sysadmin/ASR.Quotes.html http://home.xnet.com/~raven/Sysadmin/ASR.Quotes.html [search page for "mail transfer agents"]
- _mhp_ 14y ago
  I wondered why the article didn't mention JANet-style addressing, or UUCP-style bang-paths, both of which lead to more specific elements on the right. With the rise of NAT-traversal technologies, I find it a little disappointing that bang-path addressing hasn't been rediscovered and used with TURN.
  - ajross 14y ago
    Honestly I find it comforting that people who think that the solution to inconvenient addressing problems is more and different syntax haven't won the argument. :)
  - rwmj 14y ago
    Indeed .. because the article was under-researched drivel.
codev 14y ago
JANET (the UK university network) had a NRS (Name Registration Service - similar to DNS) that worked from least-to-most specific. So Cambridge was uk.ac.cam instead of today's cam.ac.uk. There were gateways to talk to email servers on ARPANET and reverse the ordering - there's more on it here: http://www.uknof.com/uknof7/Reid-History.pdf http://www.uknof.com/uknof7/Reid-History.pdf
charlieok 14y ago
When domain names were first used, there was no such thing as a URL. The end.
spindritf 14y ago
Group hierarchies on USENET were from least to most specific, for example sci.math.num-analysis.
- samatman 14y ago
  There are good reasons for both of these choices. USENET was a taxonomy, at least in principle, although like any taxonomy of thought you ran into cases like sci.foo.bar and alt.foo.bar fairly often. A taxonomy should be read from general to specific. Email addresses are addresses. The metaphor is a geography, which goes from the specific to the general. Then we have URLS, which go from the specific to the general, hit a slash, reverse direction, and then explode into a bunch of hacked-on features.
  - anonymfus 14y ago
    Addresses goes from specific to general mostly in countries influenced by British empire. Because international standard require to put city and country at the end, many countries have addresses with mixed order: street, home number, apartment number, city, country.
    - jfb 14y ago
      There are many, many, many people in the world at valid addresses never touched by the British Empire. China, Japan, Indonesia, Brazil, &c.
wazoox 14y ago
Back in the early 80s, UUCP formatted addresses such as bigvax!foobox!user where more common than user@box.network. https://en.wikipedia.org/wiki/UUCP https://en.wikipedia.org/wiki/UUCP
zokier 14y ago
So did URL get designed backwards then? Should we have cerf@example.com instead of example.com/~cerf? id=5236146?item@news.ycombinator.com maybe?
mleach 14y ago
Java Developers staring at com.domain.specific namespaces are somewhat preconditioned to examining this discrepancy.
wilfra 14y ago
"This was basically maintained in one giant text file managed by one organisation." Actually it was managed by one guy! http://en.wikipedia.org/wiki/Jon_Postel http://en.wikipedia.org/wiki/Jon_Postel
- dman 14y ago
  Thanks for linking this - Jon has an incredible legacy.
anotherbadlogin 14y ago
Too bad ICANN turned the opportunity to get rid of canned TLDs altogether into a massive sham and rip-off.
penguat 14y ago
So, is the obvious response to find a way to change our URL paths to subdomains? e.g. 5236146.item.news.ycombinator.com ? Sounds interesting but not productive, to me.

95 points by advisedwang 14y ago

Interesting. Now I wonder why Java decided to go the other way with a reversed domain name for packages. E.g., com.company-name.package-name

gabipurcaru 14y ago
well, for the same reasons the urls _should_ be the other way around, plus avoiding inconsistencies with other languages I guess (don't know what languages supported dot-named packages at that time, but I don't think they were the first ones)
syncsynchalt 14y ago
In the initial implementation package names were literally mapped to a path with the equivalent of subst(".", "/"). So in that sense the java package names are based on the hierarchy of a filesystem.
- greenyoda 14y ago
  Also, the method name goes to the right of the class name, so the only reasonable way to have a hierarchical name that reads in a single direction is to put the most general qualifier on the left and the most specific on the right: com.mydomain.mypackage.MyClass.staticMethod()

opminion 14y ago

Funny to think that if Twitter handles were fragments of email addresses they would be backwards: com.twitter@holysee --- By the way, this must be a mistake: This is a clearly a byproduct of the right-to-left language of the designers of these systems

DLWormwood 14y ago
That language is math. Which, due to historical accident, was inspired by Arabic writing, rather than the Latin variety.
- andrewcooke 14y ago
  that sounds interesting, but i'm having a hard time getting my head round it. can you give an example where math is right to left? [edit oh, numbers! thanks! i was thinking about algebra.]
  - Turing_Machine 14y ago
    Think of the standard addition and multiplication algorithms. You start with the rightmost place, right?
  - Retric 14y ago
    Think about basic math aka addition, subtraction, and multiplication work. 1237 + 4567 7+7 = 14 = 4 3+6 + 1 = 10 = 0 2+5+1 = 7 1+4 = 5 5704 That's right to left. If we wrote numbers left to right we the 1's place would be on the left.
  - lutusp 14y ago
    Sure -- Scheme: Link: http://weber.marblefalls.txed.net/mfhs/academics/electives/compsci/R0SchExprs.htm http://weber.marblefalls.txed.net/mfhs/academics/electives/c... Example: (+ 5 (* 10 x)) Which more or less means 5 + 10 * x in everyday notation. Compare to Reverse Polish Notation (used in Hewlett-Packard calculators and elsewhere), which would express the above as: 10 x * 5 +
  - T-hawk 14y ago
    Numeric notation is built right to left. To count up from 1 to 9 uses single digits, of course. Then to go from 9 to 10, the ones place increments and rolls over, and we add the new tens digit on the left, not the right.

jbert 14y ago

The UK "Grey Book" email system (http://en.wikipedia.org/wiki/Coloured_Book_protocols http://en.wikipedia.org/wiki/Coloured_Book_protocols) used email addresses the other way around (in the same timeframe that the UK was using a stack over X.25 as their internetworking protocol). For example, a user at Imperial College (IC) would have been: user@uk.ac.ic, rather than user@ic.ac.uk as they might today. Email gateways existed to convert between the different systems, but when all country codes were added to the internet, some addresses were simply ambiguous. (An address ending in .cs might be either czechoslavakia or a computer science department.) The main email software responsible for this slicing and dicing was known as PP, which helps explain the excellent quote on ASR (alt.sysadmin.recovery) a few years later: http://home.xnet.com/~raven/Sysadmin/ASR.Quotes.html http://home.xnet.com/~raven/Sysadmin/ASR.Quotes.html [search page for "mail transfer agents"]

_mhp_ 14y ago
I wondered why the article didn't mention JANet-style addressing, or UUCP-style bang-paths, both of which lead to more specific elements on the right. With the rise of NAT-traversal technologies, I find it a little disappointing that bang-path addressing hasn't been rediscovered and used with TURN.
- ajross 14y ago
  Honestly I find it comforting that people who think that the solution to inconvenient addressing problems is more and different syntax haven't won the argument. :)
- rwmj 14y ago
  Indeed .. because the article was under-researched drivel.

codev 14y ago

JANET (the UK university network) had a NRS (Name Registration Service - similar to DNS) that worked from least-to-most specific. So Cambridge was uk.ac.cam instead of today's cam.ac.uk. There were gateways to talk to email servers on ARPANET and reverse the ordering - there's more on it here: http://www.uknof.com/uknof7/Reid-History.pdf http://www.uknof.com/uknof7/Reid-History.pdf

charlieok 14y ago

When domain names were first used, there was no such thing as a URL. The end.

spindritf 14y ago

Group hierarchies on USENET were from least to most specific, for example sci.math.num-analysis.

samatman 14y ago
There are good reasons for both of these choices. USENET was a taxonomy, at least in principle, although like any taxonomy of thought you ran into cases like sci.foo.bar and alt.foo.bar fairly often. A taxonomy should be read from general to specific. Email addresses are addresses. The metaphor is a geography, which goes from the specific to the general. Then we have URLS, which go from the specific to the general, hit a slash, reverse direction, and then explode into a bunch of hacked-on features.
- anonymfus 14y ago
  Addresses goes from specific to general mostly in countries influenced by British empire. Because international standard require to put city and country at the end, many countries have addresses with mixed order: street, home number, apartment number, city, country.
  - jfb 14y ago
    There are many, many, many people in the world at valid addresses never touched by the British Empire. China, Japan, Indonesia, Brazil, &c.

wazoox 14y ago

Back in the early 80s, UUCP formatted addresses such as bigvax!foobox!user where more common than user@box.network. https://en.wikipedia.org/wiki/UUCP https://en.wikipedia.org/wiki/UUCP

zokier 14y ago

So did URL get designed backwards then? Should we have cerf@example.com instead of example.com/~cerf? id=5236146?item@news.ycombinator.com maybe?

mleach 14y ago

Java Developers staring at com.domain.specific namespaces are somewhat preconditioned to examining this discrepancy.

wilfra 14y ago

"This was basically maintained in one giant text file managed by one organisation." Actually it was managed by one guy! http://en.wikipedia.org/wiki/Jon_Postel http://en.wikipedia.org/wiki/Jon_Postel

dman 14y ago
Thanks for linking this - Jon has an incredible legacy.

anotherbadlogin 14y ago

Too bad ICANN turned the opportunity to get rid of canned TLDs altogether into a massive sham and rip-off.

penguat 14y ago

So, is the obvious response to find a way to change our URL paths to subdomains? e.g. 5236146.item.news.ycombinator.com ? Sounds interesting but not productive, to me.