# One app - multiple instances - how to maintain?

**URL:** <https://www.ruby-forum.com/t/one-app-multiple-instances-how-to-maintain/126533>\
**Category:** Rails\
**Created:** [January 19, 2008, 3:16am UTC](https://www.ruby-forum.com/t/one-app-multiple-instances-how-to-maintain/126533 "2008-01-19T03:16:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![goodieboy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ecc23a/32.png) [@goodieboy](https://www.ruby-forum.com/u/goodieboy)\
**Post date:** [January 19, 2008, 3:16am UTC](https://www.ruby-forum.com/t/one-app-multiple-instances-how-to-maintain/126533/1 "2008-01-19T03:16:58Z")

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Hi,

I’ve created basic cms/ecommerce application. I’ve got a couple of  
clients that are going to use it. I’d like to find a way to maintain  
the same code base in the back end, but customize the front.

There are a couple different schemes I’ve thought of that could solve  
the problem.

rails engines with svn externals  
my own plugin scheme that kind of does what engines does, but more  
simple. uses svn external  
subversion branches?  
KISS - keep all of it separate - manually keep track of bug fixes,  
updates etc… maybe use svn diff?

Surely a lot of you have created apps like this, where you want to  
have different instantiations, be able to customize, but have the  
ability to maintain easily?

I’m all ears 🙂