One option is POSH (used to be called Portaneo). It is not maintained very actively but it is kind of an open source version of Netvibes, or at least what Netvibes used to be.
One thing I'm not sure, is if it has password protection, but you can always set-up a login page or something with Apache/Nginx.
You can find it here, along with a clear list of features : https://sourceforge.net/projects/posh/
It was last updated two years ago, but again last I checked it was working well for what it's supposed to do (RSS, basic widgets, etc.).
EDIT :
Since the documentation is a little lacking, here's how to install it :
- You need a LAMP stack
- Copy the folder (from sourceforge, extracted) to your
www
dir
- Give ownership of the new sub dir to www-data
- Navigate to
http://host/posh_dir/install/
- In the install page indicate the db host, db user and password, and the name of the database (the db will be created). Also indicate the admin user and password for POSH.
- Done !
Since the project is not highly maintained, I suggest anyway to only use it if you're ready to get your hands dirty. In my case, I really wanted something like netvibes (as I was used to it) so it was worth it.
If you want something faster to setup and not necessarily a netvibes clone, the best option available seems in my opinion to be Smashing.