I was the maintainer of Vertimus and the 1.0.2 release is the latest one and no commit have been made beyond this tag.
As you've certainly seen the PHP code is based on the Zend Framework (around the 1.0 version).
I don't think it's a good idea to depend on unmaintained code but it's Open Source and if you know a little PHP, you could update the code for your needs.
Damned Lies is designed for the GNOME project but may be Transifex (
www.transifex.net) offers the features you want and it's more modular.
Stéphane