Simple program to keep clients in the loop?

This is a follow up to this question: Project management app for web developers?

Basically, redmine is a bit overkill. I just want to be able to:

1. Split a project into X sized chunks
2. Notify clients when sections are completed
3. Allow clients to log in at any point and s开发者_JAVA百科ee the progress of their project

Maybe there are plugins that can provide this functionality?

It would be great if this app could source the clients from WHMCS. And I really would hate to have to do this myself from scratch. :-)

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Maybe Basecamp? http://basecamphq.com/

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Try be our(Drupal) own OpenAtrium