# How does the sub-domain like urls are created in web apps?

**URL:** <https://www.ruby-forum.com/t/how-does-the-sub-domain-like-urls-are-created-in-web-apps/148271>\
**Category:** Rails\
**Created:** [September 11, 2008, 6:55am UTC](https://www.ruby-forum.com/t/how-does-the-sub-domain-like-urls-are-created-in-web-apps/148271 "2008-09-11T06:55:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rocknrollcar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/f14d63/32.png) [@rocknrollcar](https://www.ruby-forum.com/u/rocknrollcar)\
**Post date:** [September 11, 2008, 6:55am UTC](https://www.ruby-forum.com/t/how-does-the-sub-domain-like-urls-are-created-in-web-apps/148271/1 "2008-09-11T06:55:30Z")

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Hello,  
I registered in a site called basecamp. After I registered, they  
gave me a url like [http://xxx.basecamp.com](http://xxx.basecamp.com) where i have to log in access  
my project management. I heard that basecamp is built in ruby on rails.  
I couldn’t get the point of building a subdomain like url. Can anyone  
give some guidance of how to create a sub domain like url using rails?  
Thanks in advance

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<div class="post-metadata">

**Author:** ![rocknrollcar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/f14d63/32.png) [@rocknrollcar](https://www.ruby-forum.com/u/rocknrollcar)\
**Post date:** [September 11, 2008, 9:04am UTC](https://www.ruby-forum.com/t/how-does-the-sub-domain-like-urls-are-created-in-web-apps/148271/2 "2008-09-11T09:04:24Z")

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You can use subdomains for various purposes. One is to host different  
servers (eg [mail.example.com](http://mail.example.com) and [www.example.com](http://www.example.com)), or to host  
different applications (eg removed\_email\_address@domain.invalid and removed\_email\_address@domain.invalid).

I believe Basecamp use it to have nicer URLs. The standard way would  
be:  
[//www.example.com/~rockroll/](https://www.example.com/~rockroll/)…, or  
[//www.example.com/](https://www.example.com/)…?user\_id=123456

[//rockroll.example.com/](https://rockroll.example.com/)… looks nicer.

A few links:  
[http://wiki.rubyonrails.org/rails/pages/HowToUseSubdomainsAsAccountKeys](http://wiki.rubyonrails.org/rails/pages/HowToUseSubdomainsAsAccountKeys)

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>
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Christian