First, we define our requirements for a multiuser invoice system. These will help us find the right system.

The system should be available as open source and have an online demonstration or satisfying screenshots.
The system should be easy to install, easy to backup, easy to restore, easy to use, have a neat layout and use English [...]

Dear customers, users and guests, the content management system, the frame work, for our new website has now been installed and implemented.
After testing three different well known content management systems for our requirements, such as simplicity, learning curve and scalability, our choice fell on WordPress, which meet all our requirements. Among other tested systems was [...]