[TYPO3-english] how to develop extension?

[Santiago]

Hello,

I created a first extension with kickstarter and modified the php-files from the 
ext-subdir.

Then I discovered a warning from extension manager, saying that there are 
differences between installed and recent version.

I apologize for boring - but I found little to no docs on that item.

So I wonder, what is the recommended way to develop extension?
... and is there a tool available, to create those t3x-files?


kind regards

Santiago