On my first job interview, I was asked why did I build my own CMS? Why not to use one of existing CMS, Wordpress, Joomla, Drupal...? At first, I was stunned. I couldn't immediately recall all of my reasons for building my own CMS, but this was definitely one of the main reasons: It's my code and if I want to change something in that CMS (which I often have to do, because each website I build needs CMS with different functions) it's not a big problem. For some time I've been using Wordpress and one of the main things that distracted me from using it was discovering bugs in code that wasn't written by me and this bugs were often, especially if I made some changes to CMS or added a plugin...

Here, I can find these 8 reasons why NOT to build own CMS:

1. It won’t meet users’ needs

2. It’s too much work

3. It won’t be a standard solution

4. It won’t be extendible fast enough

5. It won’t be tested well enough

6. It won’t be easily changeable

7. It won’t add any value

8. Create content, not functionality

Quote from the same page:

So the main question to ask yourself is: ‘Why am I really trying to re-solve a problem that has already been solved before?’

Well, I definitely agree that it's hard to invent CMS that hasn't been already invented, but on other hand, I think every CMS is (or should be) individual... it maybe won't have a million of functions, it will have 3 functions but their usage will be clear (to a user) and do all that one site needs to have. I think also that it is not good to give to a client a CMS with a lot of functions that are never used and it looks probably more professional when website and CMS together look like one product.

I would also like to comment some quote parts:
"It’s too much work" - I agree, but when using existing CMS and customizing it to website needs and can sometimes be very hard job or mission impossible.
"It won’t be easily changeable" - I disagree with this one.

What is your opinion on this one, why did you develop or didn't develop your own CMS?
Ile